Vaccine

mRNA Vaccines – Truth vs Misinformation

Robert F Kennedy Jr has stopped funding for research to develop new mRNA vaccines because he says they don’t work well for respiratory diseases. He also claims that mRNA vaccines induce mutations in respiratory viruses. He says that even one mutation makes mRNA vaccines ineffective. Here is a link to his video post on X where he makes these claims. He also claims that he has consulted science experts who agree with him about mRNA vaccines.

In this post I will review the real science about mRNA vaccine technology, how mRNA vaccines differ from traditional vaccine technology and also discuss how viruses mutate and why (spoiler alert: they don’t mutate because of mRNA vaccines). Here is a link to a STAT news article that deconstructs Kennedy’s arguments: Kennedy’s case against mRNA vaccines collapses under his own evidence.

Traditional vaccines

There are two types of traditional vaccines, live vaccines and killed vaccines. Both types require growing the target virus in tissue culture. In a live vaccine, the virus is weakened so that infection does not cause the disease when injected into people with healthy immune systems. The MMR vaccine is an example of a live vaccine. It contains weakened strains of measles virus, mumps virus and rubella virus. Killed vaccines use some proteins from the virus to sensitize the immune system to kill the virus when it detects those proteins. the DPT vaccine is an example of a killed vaccine. It contains protein fragments from the diphtheria virus, pertussis (whooping cough) virus and tetanus virus. It is very labor intensive to create a vaccine using these traditional methods. To make enough weakened virus or virus protein fragments to immunize a large population takes a lot of tissue culture and a long time. It usually takes 10-15 years of research and development before new traditional vaccines are ready to use. Manufacturing those already approved vaccines is still very labor intensive.

What is mRNA?

The m in mRNA stands for messenger RNA. The genes in your DNA can’t do anything by themselves. They don’t directly make proteins. Instead they code for messenger RNA. Messenger RNA does the work of making proteins that determine hair color, eye color and all other genetic traits. Each type of messenger RNA is specific for a particular protein. Messenger RNA does not last very long in animal (or human) cells. It lasts from a few minutes to a few hours and then it disappears. The DNA makes more messenger RNA as needed.

How does an mRNA vaccine work?

The advantage of an mRNA vaccine is that the body does all the work of manufacturing the virus protein fragment. No intensive tissue culture is required. mRNA is synthesized in a laboratory. The synthesized mRNA codes for a specific virus protein. In the case of the COVID mRNA vaccine, the mRNA codes for the spike protein. When that mRNA is injected into a muscle, the muscle cells start to make many copies of the spike protein. The immune system recognizes this as a foreign protein and makes antibodies against it as well as sensitizing killer lymphocytes so that they recognize the protein too. Just like the body’s own mRNA, the injected mRNA only lasts for a few minutes to a few hours and then disappears. It never changes the DNA in the cell, because DNA makes mRNA, not the other way around.

How does mRNA vaccine speed up the vaccine development process?

We now have the technology to rapidly determine all the genetic code of a new virus. That sequencing can happen within a few weeks of discovering a new virus. That genetic code allows us to determine which proteins make up the virus particle. We can then decide which viral protein is the best to stimulate immunity to the virus and synthesize an mRNA molecule that will make that protein in human muscle cells. That process is much faster than the traditional method. We had an effective mRNA COVID vaccine within a year of the beginning of the pandemic. That is an absolutely unprecedented time scale in new vaccine development.

Do mRNA vaccines induce mutation in viruses

This is what Kennedy claims and it is absolutely not true. Some viruses, like COVID and flu virus mutate frequently and some like measles virus and polio virus are stable and do not mutate or mutate rarely.. The mutation rate depends on the nature of the virus, not on the vaccine. All vaccines, not just mRNA vaccines for viruses that mutate frequently lose some efficacy over time and the vaccine has to be modified. The viruses that mutate frequently would continue to do that whether a vaccine is available or not. Vaccines do not make viruses mutate faster. Most mutations make the virus less infectious, but the occasional mutation makes the virus more infective. The mutations that are more infective become more frequent and crowd out the older versions of the virus. Measles and polio vaccines prevent infection because the measles and polio viruses stay exactly the same over time.

Safety of mRNA vaccines

The only mRNA vaccine that we have extensive experience with are the ones developed for COVID. Mild reactions were common (sore arm, fever. myalgias) more commonly with the second dose. Rare cases of myocarditis (inflammation of the heart muscle) were reported in younger people. All of these were transient and completely resolved. There is a very tiny chance of having a severe allergic reaction to the vaccine. Out of 8 billion doses administered death due to allergic reaction occurred in 14 people. That is a risk of death of 1.75 x10-9 (1.75 preceded by 9 zeros!).That risk is much, much smaller than the risk of being killed in an auto accident. The risk of death from COVID in unvaccinated people is of course much higher. mRNA vaccines are safe with a minuscule risk of severe side effects.

Why do people still get influenza or COVID even after they have been vaccinated.

Antibodies induced by flu and COVID vaccines are in the blood stream and not as much on the mucus membranes. Although vaccinated people are less likely to get infected with influenza or COVID, the protection rate from infection is less than 100%. Vaccinated people can still get infected with influenza or COVID. The vaccine induced antibodies immediately start fighting the infection. This means that vaccinated people who get infected are much less likely to get severe infections, much less likely to be hospitalized and are much more likely to have mild symptoms. You get a great deal of protection from the vaccine even if you get infected with the virus. Kennedy asserts that if you get infected with the virus, then the vaccine does not work. That is poppycock!

Research into new mRNA vaccines

Researchers can now use AI to develop universal mRNA vaccines for COVID and influenza that could develop immunity to multiple genetic variants at the same time. This technology would mean that new vaccines don’t have to be developed every year to deal with new genetic variants. This technology also might make it possible to develop vaccines for malaria and leptospirosis. It may also be possible to use this technology to develop vaccines that sensitize the immune system to destroy cancer cells.

All of the federal funding for research using this promising technology has been blocked by HHS secretary Robert F Kennedy Jr.

Bottom Line

mRNA vaccines can be developed much faster than traditional vaccines. They are safe and effective at both preventing disease and making disease much milder when infection does occur. mRNA technology has the potential to make universal flu and COVID vaccines, vaccines for malaria and leptospirosis and even vaccines to prevent cancer. It is unconscionable that federal funding for this important research has been halted.

MAHA Fact and Fiction

We have all lately heard a lot about MAHA (Make America Healthy Again) from Robert F Kennedy Jr. Some of the things he is advocating probably would improve the health of Americans, but many would not only not improve health, but would make it worse. In this post I’m going to try to identify the good parts and debunk the rest.

Food Dyes

Kennedy wants to eliminate “synthetic” food dyes except for “natural” ones. Food dyes have no nutritional value and many have never been adequately tested in humans. That does not mean they are toxic or cause disease. The only food dye that has been shown to be possibly toxic to humans is red dye #3 also known as erythrosine. It has already been banned in food and cosmetics. For other food dyes we simply do not know how safe they are for human consumption. . The FDA has recently approved 3 plant based food dyes:

  • Galdieria extract blue, a blue color derived from the unicellular red algae Galdieria sulphuraria.
  • Butterfly pea flower extract, a blue color that can be used to achieve a range of shades including bright blues, intense purple, and natural greens. This dye is produced through the water extraction of the dried flower petals of the butterfly pea plant
  • Calcium phosphate, a white color approved for use in ready-to-eat chicken products, white candy melts, doughnut sugar, and sugar for coated candies.

We don’t know any more about the safety of long term use of these plant-based dyes in food than we know about synthetic dyes. Just because they are extracted from plants does not make them safer. The drug digoxin was originally extracted from the foxglove plant. Taking too much of that can kill you. The most conservative thing to do is to ban food dyes, period. That would take congressional action, which is most unlikely in the current congress.

There is no evidence, by the way, that any currently used food dyes cause cancer or other diseases. There is just very little evidence about whether they are safe or not.

Emulsifiers

Emulsifiers are added to foods to prevent separation of oil and water in foods. They also can increase shelf life. Some are natural products like guar gum and some are synthetic. Emulsifiers are not new and have been used for hundreds of years. There is some evidence that certain emulsifiers may adversely affect the gut microbiome. Most of this work has been done in mice, so it is not clear whether emulsifiers have the same effect in humans. Emulsifiers are used most extensively in processed and ultra-processed foods. Unprocessed foods do not contain emulsifiers. Once again, the jury is out on whether emulsifiers have adverse effects in humans, but they might have an effect on the gut microbiome and promote inflammation and they might not. Kennedy is opposed to all emulsifiers in food. This is not exactly a nuanced perspective, as is the case with all his recommendations and obsessions.

Other Food Additives

There are hundreds of substances added to foods. Here is a link to an FDA list of all substances added to foods that are approved by the FDA or are GRAS (generally recognized as safe): Substances Added to Food. This list is 80 pages long! I have to say that I agree with Kennedy on this one. Already, all of these additives have to be listed on the contents label. If there are more than three things on the contents label that you don’t recognize, leave it on the shelf!

Seed Oils

Kennedy (who is a lawyer, not a health expert, by the way) parrots many so called “natural” food advocates who say that seed oils have toxic by products and the wrong ration of omega 6 to omega 3 fatty acids. They maintain that seed oils cause inflammation and thus increase the risk of heart disease and other conditions like obesity and diabetes. The evidence does not support these claims.

What are seed oils anyway?

  • Canola (rapeseed) oil
  • Corn oil
  • Cottonseed oil
  • Soybean oil
  • Sunflower oil
  • Safflower oil
  • Grapeseed oil
  • Rice Bran oil

All of these are polyunsaturated (as opposed to saturated oils like animal fats, palm oil and coconut oil , which are not good for you in more than moderate amounts). They are more refined than cold pressed oils and a chemical process is used in the refining process. These chemicals, including hexane are volatile and completely evaporate during the refining process. There are no toxic by products in refined seed oils.

Health effects of seed oils – The evidence

Seed oils contain linoleic acid which is an omega 6 fatty acid. Multiple studies show that linoleic acid intake decrease the risk of heart disease and decreases , not increases inflammation. The best way to use these or any oil as a beneficial part of a healthy diet is stir frying vegetables, oven roasting fish, or crafting homemade salad dressings.

The correct ration of omega 6 to omega 3 fatty acids is not clear. To get both eat omega 3 fatty acids which are found in high amounts in walnuts and fatty fish. A good summary of the evidence on the good health effects of seed oils can be found on this Massachusetts General website: Seed Oils: Facts and Myths.

Beef Tallow

Kennedy thinks that using beef tallow for frying is healthier than seed oils. While beef tallow does make for delicious french fries, it is 100% saturated fat. Saturated fat can be healthy as a small part of your total fat intake, but eating exclusively animal fat vs unsaturated fat markedly increases the risk of heart disease, obesity and diabetes. Multiple studies over the years have confirmed increased risk from eating exclusively or large quantities of saturated fats. Kennedy has a video of him frying a whole turkey in beef tallow while saying that this is cooking the MAHA way. Here is a link to that video. In my opinion this is the height of irresponsibility.

Water Fluoridation

Kennedy cites studies that show decreased IQ in children who are exposed to fluoridated water. I have a previous post about the safety of water fluoridation. See this link. The bottom line is that these studies were done in countries and locales that had very high natural fluoride levels. There was no effect in these studies on the very low fluoride levels that are used in water supplies to prevent cavities in children. Banning water fluoridation will lead to excess tooth decay in the most vulnerable children.

Limiting foods that can be purchased with SNAP benefits

SNAP stands for Supplemental Food Assistance Program. It used to be called the food stamp program. Benefits are applied to a card that can be used like a credit card to purchase food. As of now households whose gross income is 130% or less of the federal poverty and whose net income is below the federal poverty level are eligible for SNAP benefits. The amount is determined by the number of people in the household. The federal government pays all of the benefits and 50% the administrative costs. The state pays the other half of the administrative costs. The Big Beautiful Bill Act will make substantial cuts to the SNAP program. More about that later.

People can use their SNAP benefits to purchase food, but not alcohol or cigarettes. Texas and Louisiana have just passed laws that also prevent using SNAP benefits to purchase soft drinks or candy. Kennedy has praised these new state laws. While it is true that soft drinks and candy are not healthy foods, excluding these from SNAP benefits is just a way to make lawmakers feel virtuous about limiting the food choices poor people make. It is not going to improve their nutrition because like non-SNAP households foods households buy on SNAP benefits tend to be ultra-processed foods. Healthy unprocessed foods are more expensive and require time to prepare and cook as well as requiring working appliances and cooking equipment. Families at or below the poverty level, who are often renting sub-standard housing are unlikely be able to afford to purchase or to have the time, and equipment to prepare and cook unprocessed foods. Non-SNAP households don’t do much better. See this link from the USDA: Foods typically purchased by SNAP households .One more MAHA recommendation that will likely not improve health!

What makes this even worse are the cuts to the SNAP program in the Big Beautiful Bill Act. Here is a summary of the cuts and when they will kick in:

  • Shifting SNAP costs to states by:
    • Requiring states to pay a portion of SNAP benefits for the first time in program history, up to 15%, based on their payment error rates, beginning in October 2027. Final negotiations in the Senate resulted in a temporary implementation delay for up to two years for states with high error rates. 
    • Increasing the state’s share of administrative costs from 50% to 75%. 
       
  • Restricting future adjustments to the Thrifty Food Plan, which will include cuts to SNAP benefits as well as benefit levels for The Emergency Food Assistance Program (TEFAP), SUN Bucks/Summer EBT benefits, and the Nutrition Assistance Program block-grant to Puerto Rico. 
     
  • Increasing the number of individuals subject to time limits on their SNAP benefits, including, for the first time ever, parents of school-aged children over 14 and older adults age 55 through age 64 by expanding work requirements and restricting waivers. 
     
  • Adds a time limit on benefits for veterans, currently homeless individuals and former foster care youth.
  • Eliminating funding for the SNAP Nutrition Education program. 

SNAP is (or was) the most effective hunger relief program in the U.S.

All of the above information on the changes to SNAP benefits comes from the Harvesters Community Food Network .

Vaccines

With no evidence whatever, the MAHA report calls current childhood vaccination schedules “overmedication.” It emphasizes exceedingly rare adverse effects of vaccines and promises to do “randomized trials” of current vaccine schedules. Randomized trials are routinely done before new vaccines are approved and repeating them will be inordinately expensive and delay vaccine approval. The result of this MAHA policy will mean that we will see serious childhood diseases again, some of which will result in hospitalization and some totally avoidable childhood deaths. We have already seen a resurgence of measles cases in 40 states. See my previous post about Vaccine risks in perspective.

Bottom Line

Kennedy has legitimate concerns about the unhealthy ultra-processed foods that most Americans eat. The concerns about food additives are also reasonable but overblown. These legitimate concerns are mixed in with conspiracy theories about toxic byproducts in seed oils, health benefits of beef tallow, and vaccines as a cause of autism. He completely ignores the fact that most poor people cannot afford to buy, prepare or cook healthy unprocessed foods. He is overall a danger to public health.

MMR Vaccine Risks in Perspective

This post is a follow-up to my recent post about measles and MMR vaccine. The purpose of this post is to compare the risk of adverse effects from the MMR vaccine to other risks that we take with our children every day.

Annual Deaths of children under 18

In the US 37,000 children under the age of 18 die every year. In 2022, the last year for which we have complete data, 604 children were killed in automobile accidents. This figure includes those killed as passengers, walking to school or in their neighborhoods, or riding their bicycles. Here is a table from the New England Journal of Medicine showing the most common causes of death of children since 1999.

As you can see from the graph, motor vehicle deaths of children have gone down significantly since 1999, but are still the second leading cause of death in children. Firearm injuries have now surpassed motor vehicle deaths as the leading cause of death in children.

All of these risks are small, the highest being 4.5 deaths per 100,000 Children. These are risks we take with our children every day. There is a risk when they ride in your car. There is a risk when they walk in their neighborhoods. There is a risk when they ride their bicycles. There is a risk that they will be killed by a mass murderer when they go to school. The risks of adverse reactions to vaccines are actually lower than the risks that we take with our children every day. Adverse reactions to vaccines almost never kill children

Deaths of children due to MMR vaccine

There have been only two documented deaths due to MMR vaccine in the 62 years it has been available. Both of these deaths were in children with Severe Combined Immunodeficiency Syndrome (SCIDS). You may remember a movie about a child with this syndrome. It was called “The Boy in the Bubble.” These children should never have received a live virus vaccine, such as MMR.

MMR Vaccine and Autism

Robert F. Kennedy Jr, the current head of HHS, has contended that MMR vaccine causes autism. There was a paper published by Andrew Wakefield in the medical journal, the Lancet, that studied 12 children and concluded that MMR vaccine was linked to autism. It was later discovered that he had falsified his results and the paper was retracted by the Lancet. This discredited paper, plus another one by the same author are still cited by people, including our current head of HHS, as evidence that MMR vaccine causes autism.

Study by Brent and Taylor

Brent and Taylor and colleagues examined the records of 498 children with autism. Cases were identified before and after MMR vaccine became available in the UK. They compared the incidence of autism in vaccinated and unvaccinated children and found no difference.

Study by Madsden and Colleagues

Madsden and colleagues did one one of the best and most rigorous studies. The study included 537,303 children representing 2,129,864 person-years of study. Approximately 82% of children had received the MMR vaccine. The risk of autism in the group of vaccinated children was the same as that in unvaccinated children. Furthermore, there was no association between the age at the time of vaccination, the time since vaccination, or the date of vaccination and the development of autism.

Other studies

Many other well designed studies have shown no association between the MMR vaccine and autism.

Bottom Line

We daily accept small risks of injury and death of our children. There are no activities involving children that are without some risk. The risks of MMR vaccine side effects (or any other vaccine) are no larger than the risks we take with our children every day. See my last post for a list of possible side effects of MMR vaccine. Severe side effects of MMR vaccine are very rare. When given appropriately to children with normal immune systems, death is not one of the risks. The one study by Andrew Wakefield that showed a connection with MMR vaccine and autism was shown to be fraudulent and was retracted. Multiple well designed studies have definitively shown that MMR vaccine does not cause autism.

Antivaxxers – What Motivates Them?

The scientific evidence is clear that vaccines, starting with the smallpox vaccine developed by Edward Jenner in 1796 have saved millions of lives. Mild adverse reactions such as fever, sore arm and fatigue are relatively common. Serious adverse reaction to any and all vaccines in use today are extremely rare, on the order of one in a million. These serious reactions are almost always severe allergic reactions that occur immediately and can be treated successfully.

Despite the overwhelming evidence of the safety and efficacy of vaccines, there have always been people who were opposed to vaccines starting with the smallpox vaccine in the 1790’s. Recently, perhaps due to the influence of social media, there are an increasing number of people who think that vaccines are harmful and refuse them for themselves and their children. These beliefs tend to be strongly held and not very amenable to change even when they are presented with the scientific evidence.

In this post I’m going to write about the reasons antivaxxers give for refusing vaccines and explore some possible reasons that it is so hard to change these erroneous beliefs.

Concerns about Safety of Vaccines

Autism

In 1998 Andrew Wakefield and twelve other authors authored a paper that was published in the New England Journal of Medicine suggesting that the MMR vaccine was associated with autism. The paper was eventually found to be based on fraudulent data and it was retracted. In the aftermath of the Wakefield article several large well designed studies showed no evidence of a connection between MMR or any other vaccine with autism. Nonetheless many people opposed to vaccines continue to site the discredited Wakefield paper.

Pertussis Vaccine

In the 1950’s there were some reports of children developing seizures after pertussis immunizations. An extensive review of these cases found no evidence that pertussis vaccine was the cause of the seizures. Because of public concern, the pertussis vaccine was reformulated so that it did not contain dead pertussis bacteria. This is now called acellular pertussis vaccine so that the combined diphtheria tetanus and acellular pertussis vaccine is abbreviated DTaP.

Thimerosal

In the 1960’s some people became concerned that some of the components of vaccines were toxic. The biggest concern was about a preservative called thimerosal, which contained a small amount of mercury. The vast majority of studies showed no evidence of any association between thimerosal exposure in vaccines and any adverse neurologic outcomes, but a few studies showed a slight association. Since 2001, no vaccines contain thimerosal.

Aluminum

Many vaccines contain a small amount of aluminum which serves to as an adjuvant, which means it increases the effectiveness of the vaccine. In large doses aluminum can cause neurological problems and autoimmune diseases. Some people have been concerned about the safety of aluminum in vaccines. Some people think Aluminum in vaccines causes autism. Aluminum is present in food and water in much higher doses than that present in vaccines. It is poorly absorbed and what is absorbed is quickly excreted in the urine.  An FDA analysis shows that the body burden of aluminum following injections of aluminum-containing vaccines never exceeds safe US regulatory thresholds based on orally ingested aluminum even for low birth-weight infants. As noted previously a possible link to autism has been disproved by several large well designed studies.

Formaldehyde

Some people have expressed concern that formaldehyde in vaccines is toxic for children. Formaldehyde has a long history of safe use in the manufacture of certain viral and bacterial vaccines. It is used to inactivate viruses so they don’t cause disease and to detoxify bacterial toxins, such as the toxin used to make diphtheria vaccine. Almost all the formaldehyde is removed in the manufacturing process, but tiny amounts can remain. The body actually makes more formaldehyde which it uses in DNA synthesis than the tiny amount that remains in vaccines.

Lack of Trust

Although all of these concerns about toxins in vaccines have been addressed or disproved, there are still some people who lack trust in the vaccine manufacturers, the medical system and the CDC whose Advisory Committee on Immunization Practices (ACIP) makes recommendations for vaccine administration. Because of this mistrust, no amount of evidence from these groups will convince these people that vaccines are safe.

Religious Objections to vaccines

Although no major religions are opposed to vaccines, certain religious groups refuse vaccination. One common religious objection is that certain vaccines are manufactured by growing virus in fetal fibroblast cells from an aborted fetus. These cells were originally obtained from two aborted fetuses in the 1960’s. The cells have been cultured since then, so it is not necessary to obtain any more cells from fetuses. The viruses are separated from the cells, so that vaccines contain no fetal tissue. The vaccines that are grown in fetal fibroblast cells are the live virus vaccines including measles, mumps, rubella, chicken pox, the Imovax vaccine for rabies and the Janssen vaccine for COVID-19.

Opposition to Mandates

Americans are overwhelmingly supportive of all vaccination mandates with support ranging from a high 90 percent of respondents for DTaP, polio, chickenpox, and MMR to a low of 68 percent for COVID-19. Support of the HPV vaccine is somewhat lower, but still more than 50%. A smaller number of people feel that they should not be forced to vaccinate themselves or their children through state mandates. Some of this group may be willing to receive vaccinations if they feel they have a choice.

Philosophical Objections

There is a group of people who see some benefit in having their children contract certain preventable diseases. Some parents believe that natural immunity is better for their children than is immunity acquired through vaccinations. Others express the belief that if their child contracts a preventable disease, it will be beneficial for the child in the long term, as it will help make the child’s immune system stronger as he grows into adulthood. Some parents believe that the diseases for which we vaccinate are not very prevalent so their children are at minimal risk of contracting these diseases. For this reason, they also believe that the possible negative side effects of vaccine administration outweigh the benefits of the vaccines. Many parents do not see the preventable diseases as serious or life-threatening and would prefer to not put extra chemicals into their children’s bodies. Other parents think if their children have healthy diets and lifestyles they are at a decreased risk of contracting preventable childhood diseases. They also are under the assumption that if they were to contract one of the diseases that it would be easily treatable. Although all of this sounds reasonable on the surface it is absolutely wrong. See the good reasons to administer vaccinations in one of the sections below.

Conspiracy Theorists

Some people have a worldview that it’s commonplace for groups of elites to conduct elaborate and sinister hoaxes on the public, and to do so in near-perfect secrecy. They think this is just how the world works, and to believe anything else is naïve. There is a very strong correlation’s between conspiracy thinking and vaccine resistance.

Beliefs about conspiracies are very difficult to change. Evidence presented against the conspiracy by health care professionals are seen as part of the conspiracy. Conspiracy beliefs about vaccines can include believing the pharmaceutical companies or the CDC are covering up adverse effects of vaccines including that they cause autism.

Desire for Additional Information

Some parents are concerned about what they have seen on social media about vaccines and just want more information from health professionals about the safety and reasons for vaccines. This type of vaccine hesitancy is the most amenable for change by providing honest and clear information about the safety of vaccines.

The Good Reasons to Give Recommended Vaccines

It is true that many (but not all) of the diseases preventable by vaccines were relatively mild in most children. Prior to vaccines, however, 30 per cent of children died before the age of 5 from infectious diseases that are treatable or preventable today. Parents today have never seen a child with diphtheria, whooping cough, or tetanus. These were diseases that killed children prior to the vaccines and they could recur if enough people refuse vaccines.

Polio

The polio virus attacks the nervous system in children. It was a feared disease in the late 19th and early 20th century. In an outbreak in the early 1950’s. Over 2000 people died and many children had permanent paralysis. Paralysis of the respiratory system led to many children being placed in external respirators called iron lungs. Epidemics tended to occur in the summer. Parents kept children away from public gatherings like swimming pools and movie theaters. On April 12, 1955 the Salk vaccine was introduced and mass immunizations began, often in schools. Cases dropped dramatically. Several years later the Sabin oral polio vaccine was introduced. It was so effective that polio was completely eradicated in the United States. Polio vaccine is therefore no longer recommended for children in the US. Pockets of polio virus infection remain in other parts of the world. The most recent cases were in Gaza during the Israeli invasion of Gaza. Emergency vaccination of children in Gaza were carried out and the disease was brought under control.

Measles

Although measles is a relatively mild disease for most children it can be very severe and cause death for some. Before the introduction of measles vaccine in 1963 and widespread vaccination, major epidemics occurred approximately every two to three years and caused an estimated 2.6 million deaths each year.

Mumps

Mumps prior to the mumps vaccine was very common and mild in most children. Complications of mumps include inflammation of the testes, ovaries and pancreas, hearing loss, meningitis, and encephalitis. These are more common in adults than in children. Mumps was one of the most common causes of aseptic meningitis and hearing loss in children in the United States prior to the introduction of the vaccine.

Rubella

Rubella (German measles) is a mild disease but if contracted by a pregnant mother can result in severe fetal deformities and sometimes still birth. The rubella vaccine prevents rubella infection.

Influenza

Influenza occurs in epidemics. One strain in 1918 caused a pandemic with millions of deaths. There are always deaths from influenza in unvaccinated people every year. Influenza vaccine is effective in preventing or reducing the severity of illness. The influenza virus develops new mutations easily, so the vaccine has to be changed every year. The flu season in the southern hemisphere occurs during our summer, so flu vaccines for the northern hemisphere are developed based on the strains found to be circulating in the southern hemisphere flu season. This process can cause some variation in the effectiveness of the flu vaccine from year to year, but it always offers some protection and reduces the severity of illness from influenza virus.

Haemophilus Influenza

Before the Haemophilus influenza vaccine, this bacteria was the leading cause of bacterial meningitis, joint infection and ear infection in children. This vaccine was introduced after I was already in practice. I treated one case of bacterial meningitis in a child and several joint infections caused by H-flu. After widespread vaccination, I never saw another case.

Varicella (Chicken Pox)

Varicella is a very infectious disease in childhood. There are a few people, especially young infants who have severe disease requiring hospitalization. In the 25 years before the varicella vaccine was available there were over 2000 deaths from varicella. Giving the vaccine at 12-15 months of age protects vulnerable infants, and older people with chronic disease.

Human Papilloma Virus

The human papilloma virus (HPV) , which is transmitted by sexual intercourse, causes cervical cancer in some infected women. The HPV vaccine, given to preadolescent girls and boys prevents 90 % of cervical cancer in women.

Respiratory Syncytial Virus (RSV)

Most children and adults with RSV have mild cold-like symptoms with cough. About 3 per cent of babies with RSV have severe disease and require hospitalization and sometimes have to be placed on a mechanical ventilator. Young infants are more at risk as well as older adults, especially those with chronic disease. There is a vaccine for both babies and adults that is very effective at preventing RSV.

Rotavirus

Rotavirus is a highly contagious virus that infects the lining of the intestines. Symptoms include: High fever, Severe and persistent vomiting, and Diarrhea. It can usually be treated at home, but can cause severe dehydration. Prior to the availability of the oral rotavirus vaccine rotavirus was a leading cause of severe diarrhea in infants and children. There were 70,000 hospitalizations a year for rotavirus and 20-60 deaths per year. The oral vaccine is very effective at preventing rotavirus infection.

Hepatitis b

Hepatitis b can be contacted through sexual intercourse or by contaminated needles. Unlike hepatitis C, there is no effective treatment for hepatitis b. Hepatitis b can cause cirrhosis of the liver as well as liver cancer. Initially the vaccine was given only to high risk people, but it turned out that we were really bad at identifying who was at risk. Hepatitis b vaccine is now given to all babies and it has essentially eliminated hepatitis b.

Pneumoccocus

Before the vaccine, every year pneumococcus caused about 700 cases of meningitis, 17,000 cases of bloodstream infections, 200 deaths and 5 million ear infections in children. The pneumococcus vaccine is very effective at preventing these infections.

Meningococcus

Meningococcus is a bacterium that can cause meningitis or blood stream infection (sepsis). When it occurs It can be treated with antibiotics if caught quickly enough but it progresses so rapidly that people are deathly ill by the time they make it to the doctor. There is now a vaccine to prevent meningococcus infection. It is recommended for all adolescents between ages 11 and 12.

Shingles

Shingles is a reactivation in adults of childhood infection with chicken pox. It is a painful blistering rash along the distribution of a nerve on one side of the body. It can occur on any part of the body. Some people have persistent pain long after the rash is gone. This is called post herpetic neuralgia. Two doses of the vaccine called Shingrix is 98% effective at protecting adults from developing shingles. It is recommended for all adults age 50 and over.

Bottom Line

People can be opposed to receiving vaccines for themselves or their children for many reasons. Some people who just want more information can often be convinced of the safety of vaccines and then agree to be vaccinated. Other reasons such as mistrust of medical and public health sources of information and conspiracy thinking are very resistant to change. Philosophical objections including the belief that getting childhood illnesses gives better immunity and the low risk of infection of vaccine preventable diseases obviates the need for vaccinations are also resistant to change. The diseases that current vaccines prevent, although often mild in most people all have caused hospitalizations and deaths in the period prior to vaccine availability. All current vaccines have been shown to be very safe and associated with only mild transient side effects. Serious reactions to vaccines are extremely rare (on the order of one in a million) and are almost all amenable to treatment.

Mosquito Borne Diseases: Risks, Prevention & Treatment

Diseases carried by mosquitos have been in the news recently. Dr. Fauci had West Nile virus, which is carried by mosquitos. Some parks in Massachusetts have started an evening curfew because of cases of Eastern Equine Encephalitis, another mosquito borne disease. Mosquito borne diseases are rare in the US, but worldwide, mosquitos are the deadliest animal in the world. Worldwide, mosquito borne diseases kill 2.7 million people a year, 90% of which occur in Africa. As climate change causes increased global warming we are likely to see an increase in mosquito borne diseases in the US. In this post I will catalog all the mosquito borne diseases, which species of mosquitos carry them, and what areas have the most risk. Only a few species of mosquitos transmit diseases, but that information is primarily useful for epidemiologists and public health specialists. When a mosquito bites you, you are not going to know what species it is!

West Nile Virus

West Nile Virus is the most common disease transmitted by mosquitos, primarily by mosquitos of the culex species. Mosquitos get infected from birds and birds can get infected from infected mosquitos, so the disease passes back and forth between birds and mosquitos. People who get infected with West Nile cannot transmit it back to mosquitos that bite them.

Symptoms

Most people infected with West Nile virus do not have any symptoms but about 1 in 5 people who are infected develop a fever, headache, weakness, muscle pain, or joint pain, gastrointestinal symptoms and a transient rash. The illness usually lasts a few days, but can last for weeks. About 1 out of 150 infected people develop serious illness that invades the brain and spinal cord. This is called neuroinvasive illness. Sometimes this is fatal and if a person survives it they are likely to have permanent disability.

Species of mosquitos that carry it

Culex especially culex tarsalis

Treatment

There is no treatment or vaccine, so avoiding mosquito bites is the only way to keep from getting it when it has been identified in your area. I will write about the ways to avoid mosquito bites near the end of this post.

Who is at risk?

Cases are primarily in the summer and fall. Cases of West Nile disease have been reported across the continental United States. The CDC keeps track of human cases and cases identified in dead birds. West Nile virus occurs in epidemics in some years with few cases in others. So far in 2024 in the US there have been 289 cases of people with non-neuroinvasive West Nile illness and 189 cases of the serious neuroinvasive disease. Since 80% of infected people have no symptoms, that means the number of people with non-neuroinvasive infection so far this year is likely 5 x 289 = 1445. That is still a tiny percentage of the entire US population. Here is a link to the CDC web page showing 2024 West Nile cases by state and by county: West Nile Current Year Data (20240. If you live in an area where West Nile virus has has been identified in birds or humans, then you are at some increased risk.

Eastern Equine Encephalitis

The virus is maintained in fresh water hardwood swamps by birds and a particular species of mosquito called Culiseta melanura. This mosquito almost exclusively bites birds, so is not a significant risk to humans. The problem comes when infected birds are bitten by other species of mosquitos that do bite humans. Those species can infect humans.

Symptoms

Fortunately this is a rare disease. Thirty per cent of people infected with this virus die. Those who survive often have serious neurological problems. Symptoms are  fever, headache, vomiting, diarrhea, seizures, behavioral changes, and drowsiness.

Species that transmit the disease to humans

Aedes, Coquillettidia, and Culex

Treatment

There is no vaccine or treatment for Eastern Equine Encephalitis. Avoiding mosquito bites is the only prevention. More about how to avoid mosquito bites later in this post.

Who is at risk?

Most cases are in the Eastern US. There have been only 4 cases so far this year according to the CDC data, but there was a death from a case just in the last few days in New Hampshire. The states that have recorded cases so far this year are Vermont, Massachusetts, New Jersey, Wisconsin and now New Hampshire. People who live in the northeast may need to be especially careful this year.

Cache Valley Virus

This virus is named for the Cache Valley in Utah where it was first recorded. It is very rare. Less than 10 cases have ever been reported. It has been reported in Illinois, Michigan, Missouri, New York, North Carolina, and Wisconsin. It is a severe disease.

Symptoms

Symptoms include stiff neck, confusion, loss of coordination, difficulty speaking, or seizures.

Species that transmit the disease

The virus has been found in several species (Anopheles, Culiseta, Coquillettidia). The main species that transmits the disease is not known.

Treatment

There is no vaccine or treatment. Avoiding mosquito bites is the only prevention. More about how to avoid mosquito bites later in this post.

Who is at risk?

This disease is so rare that there is no particular region of the US that is at risk. Mosquitos carrying the Cache Valley virus have been found in many additional locations in North America and in parts of Central America.

Jamestown Canyon Virus

The virus is maintained by mosquitos biting infected animals, mostly deer. Mosquitos cannot transmit disease from biting infected humans, so humans are considered a “dead end” host.

Symptoms

This is another relatively rare disease, but more frequent than Cache Valley Virus. Most infected people do not have symptoms, but a few people get severe neuroinvasive disease. The CDC counts only the severe cases, so the number of cases substantially underestimate the number of people infected. There are about 23 severe cases reported a year, mostly in the spring through fall. Symptoms include fever, fatigue and headache. Some people have respiratory symptoms such as cough, sore throat or runny nose. Symptoms of severe disease can include stiff neck, confusion, loss of coordination, difficulty speaking, or seizures. Death is rare from this disease.

Species that transmit the disease

Aedes, Culex, Coquillettidia

Treatment

There is no vaccine or treatment. Avoiding mosquito bites is the only prevention.

Who is at risk

Jamestown virus is found through most of the US, but Minnesota and Wisconsin have reported more than half of the cases. Again, there is no vaccine or treatment. Prevention is again the best option.

LaCrosse Virus

La Crosse virus circulates in the environment between tree hole breeding mosquitoes and small mammals, such as chipmunks or squirrels.

Symptoms

Most infected people do not have symptoms, but the disease can be severe especially in children under 16 years of age. Initial symptoms can include fever (usually lasting 2-3 days), headache, nausea, vomiting, fatigue , and lethargy. Symptoms of severe disease include high fever, headache, neck stiffness, stupor, disorientation, coma, seizures, muscle weakness, vision loss, numbness, and paralysis. Most patients recover but death from LaCrosse virus happens rarely.

Species that transmit the disease

 Eastern tree hole mosquito (Aedes triseriatus). The tree hole mosquito is found almost exclusively in wooded or shady areas, and usually does not fly more than 200 yards from the area where it developed.

Treatment

There is no vaccine or treatment Avoiding mosquito bites is the only prevention.

Who is at risk?

Most cases occur in the upper Midwestern, mid-Atlantic, and southeastern states. LaCrosse virus is a rare disease. So far in 2024 there have been 13 cases of LaCrosse disease reported from Tennessee, North Carolina and South Carolina.

St Louis Encephalitis

St Louis Encephalitis virus circulates in the environment between mosquitos and birds.

Symptoms

Most infected people do not have symptoms. Severe disease usually occurs in older or immunocompromised people. Symptoms are fever, headache, dizziness, nausea, and generalized weakness. People with severe disease can develop stiff neck, confusion, disorientation, dizziness, tremors, and unsteadiness. 5-20% of infected people die from this disease. The risk of dying increases with age.

Species that transmit the infection

Culex

Treatment

There is no vaccine or treatment. Avoiding mosquito bites is the only prevention.

Who is at risk

In recent years sporadic cases and outbreaks have occurred in the Southwest. This is a rare disease and there have been no cases reported in 2024. In some years there are outbreaks primarily in urban areas. Again there is no vaccine or treatment for St Louis Encephalitis.

Dengue

Unlike many of the diseases discussed previously, Dengue virus circulates between humans and mosquitos. Mosquitos who bite infected people then spread the virus by biting other people. People can get Dengue multiple times.

Symptoms

Most infected people have no symptoms but 1 in 4 have symptoms which include Fever and bone and muscle pain. The pain can be severe. Dengue is also known as “break bone fever.” About 1 in 10 people who get sick have severe Dengue. Severe Dengue can result in shock, internal bleeding, and death. People with Dengue who have any of the following symptoms should go immediately to a hospital emergency department: belly pain or tenderness; vomiting; bleeding from the nose or gums; vomiting blood or blood in the stool.

Species that transmit the infection

Aedes.aegypti and Aedes.albopictus

Treatment

There is a vaccine for Dengue but it is only recommended for children who have already had one episode of Dengue. It is not available in the US. The only treatment is hospitalization and supportive care for severe illness.

Who is at risk?

Most Dengue in the US is in travelers from endemic areas. Endemic areas include the Caribbean, Central America, South America, Southeast Asia and the Pacific Islands. Many of these are popular tourist destinations, so the biggest risk for US citizens is travel to one of these regions. There have been some local outbreaks of Dengue in the US in Florida, Hawaii, Texas, Arizona, and California.

Treatment

Once again, other than the vaccine for children who have already had Dengue, treatment is supportive hospital care for people with severe Dengue. Travelers to endemic Dengue areas should use mosquito bite preventive measures, discussed further later in this post.

Chikungunya

Chikungunya virus, like Dengue, circulates in mosquitos and humans. Mosquitos become infected by biting a person with chikungunya virus and then spread the virus by biting other humans.

Symptoms

The most common symptoms are fever and joint pain and can include headache, muscle pain, joint swelling, or rash. Most patients feel better within a week, but joint pain can be severe and disabling and might persist for months. Death from chikungunya virus is rare.

Species that transmit the disease

Aedes.Stegomyia, Aedes.aegypti and Aedes.albopictus

Treatment

There is a vaccine for chikungunya. Travelers traveling to endemic areas may want to consider vaccination. There is no specific treatment. Avoiding mosquito bites is the only prevention.

Who is at risk?

There have been no cases of chikungunya in the US and US territories since 2019. Travelers to endemic areas are at risk. Endemic areas include Africa, the Americas, Asia, Europe, and islands in the Indian and Pacific Oceans. Travelers should check with the CDC travel website to see if outbreaks are occurring at their destinations.

Zika Virus

Like Dengue and chikungunya, Zika circulates between mosquitos and humans. If a mosquito bites a person infected with Zika virus in the first week of infection, the mosquito carries Zika to the next person it bites. Zika can also be transmitted through sex and can be transmitted from a pregnant mother to her fetus. Zika can cause severe birth defects when a pregnant mother is infected.

Symptoms

Most infected people have no symptoms, and when symptoms occur they tend to be mild. They include fever, rash, headache, joint pain, conjunctivitis (red eyes) and muscle pain. Symptoms are rarely severe enough to need hospitalization. The biggest problem with Zika is the birth defects caused by infection of pregnant women.

Species that transmit the disease

Aedes. aegypti and Aedes. albopictus

Treatment

There is no vaccine or treatment for Zika virus.

Who is at risk?

There have been no local cases of Zika in the US or US territories since 2019. People most at risk are travelers to countries that have outbreaks. Outbreaks occur in Mexico and South America and in certain countries in Africa and India. Other countries including the US have the Aedes species that can transmit Zika. Travelers to these areas should check with the CDC about current Zika outbreaks.

Yellow Fever

Yellow fever virus is maintained in forests between mosquitos and monkeys. People who work in forests where monkeys live can contract the virus this way. Mosquitos biting infected people can also spread the virus when mosquitos bite other people. Epidemics in urban areas occur this way.

Symptoms

Most people infected with yellow fever virus will either have no symptoms or mild symptoms and completely recover. Symptoms can include sudden onset of fever, chills, severe headache, back pain, general body aches, nausea, vomiting, fatigue, and weakness. Most people who develop symptoms improve within one week. A few people will develop a more severe form of the disease. Severe symptoms include high fever, yellow skin or eyes (jaundice), bleeding, shock, and organ failure. Among those who develop severe disease, 30-60% die

Species that transmit the disease

Primarily Aedes Aegypti

Treatment

There is an effective vaccine for prevention of yellow fever. Travelers going to an endemic yellow fever region should receive the vaccine before they travel. There is no treatment once someone has yellow fever.

Who is at risk?

There is no local transmission of yellow fever in the US. Yellow fever in travelers only rarely occurs. Yellow fever is endemic in Africa and South America.

Malaria

Malaria is caused by a parasite that resides in the liver and then infects red blood cells. It is maintained by circulation between mosquitos and humans. Mosquitos get infected from biting humans with malaria and then can transmit the parasite by biting other humans.

Symptoms

Malaria symptoms range from very mild illness to severe disease and even death. Early symptoms can include: Fever and flu-like illness, Chills, Headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. If not treated quickly, the infection can become severe. Severe symptoms can include kidney failure, seizures, mental confusion, coma and death.

Species that transmit the disease

Anopheles

Treatment

Malaria can be treated successfully with several different drugs depending on the type and resistance. There are drugs that travelers can take if they are traveling to an area where malaria is present that will prevent infection. The newest development is a malaria vaccine that can be given to children in endemic malaria regions.

Who is at risk?

There is virtually no local transmission of malaria in the US in modern times. In a typical year, the U.S. reports about 2,000 cases of malaria, almost all of which are in travelers who have been to an endemic region. Malaria occurs only in tropical regions and below 6,500 feet above sea level. Most cases of malaria occur in sub-Saharan Africa, but it also occurs in parts of Oceania (such as Papua New Guinea) and in parts of Central and South America and Southeast Asia. Worldwide, malaria has caused 608,000 deaths in the past year. Malaria is one of the world’s most severe public health problems, with nearly half of the world’s population at risk for infection.

How to prevent mosquito bites.

Indoors

Make sure all windows have screens and any holes in the screens are patched. Use air conditioning if you have it during the spring and summer when mosquitos are most active.

Outdoors

Mosquitos lay eggs in standing water. Remove or empty any receptacles outside that allow water to pool such as saucers under flower pots. Tightly cover any water storage containers. If you have a birdbath, use a battery or solar powered agitator. Mosquitos only lay eggs in still water.

Residential outdoor misting systems that use permethrin provide good mosquito control and are safe for humans, birds and animals. They are somewhat expensive, however.

Use an EPA-registered insect repellant with one of the following ingredients:

  • DEET (Has been shown to be non-toxic for humans and repels but does not kill insects)
  • Picaridin (known as KBR 3023 and icaridin outside the United States)
  • IR3535
  • Oil of lemon eucalyptus (OLE)—A plant-derived ingredient (must be applied more frequently than DEET)
  • Para-menthane-diol (PMD)
  • 2-undecanone—A plant-derived ingredient

Wear loose long sleeved shirts and long pants when outside when mosquitos are active

Treat items such as boots, pants, socks, and tents with permethrin or buy permethrin-treated clothing and gear.

Bottom Line

Mosquitos transmit many diseases, but all of these are quite rare in the US. Global warming may well increase mosquito transmitted diseases in the US in the future. The vast majority of mosquito bites in the US are just a nuisance and do not transmit disease. In other parts of the world mosquito disease transmission is a major public health problem. Travelers to areas where mosquito borne diseases are prevalent should use mosquito bite prevention strategies, especially EPA-approved insect repellents. Travelers to areas endemic for yellow fever should be vaccinated prior to travel. Travelers to malaria prevalent regions should start preventive medicine 1 week before and continue 1 week after travel.

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Immunizations: What You Need to Know

This is an update and modification of an old post titled Immunizations. It seems particularly relevant now given the politicization of the whole subject of immunization in the last few years.

Many parents are concerned about the number of immunizations that are recommended for their children and whether all these shots may have some serious long term side effects. Public health recommendations that ignore these concerns have created an adversarial situation that is not helpful for parents or for their children.

To put this in perspective, lets look at the current immunization recommendations for infants and children Number of shots will be placed in parenthesis.

Newborns: Hepatitis B (One shot)

Two Months: Hepatitis B, Tetanus-Diphtheria-Pertussis, H-flu, Pneumonia, Polio, Rotavirus (Six  shots). That’s a lot of needle sticks for a baby! Fortunately there are combined vaccines that reduce the number of shots.  Using the combined vaccines reduces the number of shots at two months from six shots to three shots.

Four Months: Same as two months  except no Hepatitis B (three shots using combined vaccines)

Six Months: Hepatitis B, Rotovirus, Tetanus-diptheira-Pertussis, H-flu,  pneumonia, Polio, flu shot, COVID-19 (four shots using combined vaccines) Another COVID-19 vaccination is recommended 4 weeks after the first one.

One Year: Polio, flu shot, Measles-Mumps-Rubella, Chicken pox, Hepatitis A (Four shots using combined vaccines).

Four Years: Tetanus-Diphtheria-Pertussis, Polio, Measels-Mumps-Rubella, Chicken pox (three shots using combined vaccines).

Nine Years: HPV vaccine. Second dose in 6 months to 1 year. HPV vaccine prevents infection with the wart virus also called human papilloma virus. HPV is the main cause of cervical cancer in women. It is transmitted through sexual intercourse. Given at age 9, the immunity is lifelong so immunizing children (girls and boys) means that as adults, when they become sexually active, there will be much less transmission of HPV and much less cervical cancer in women.

That’s a lot of shots, even with the combined vaccines, not even counting the HPV vaccinations recommended at age nine..  So one question is: Is the benefit of all these shots worth the discomfort to the children (not to mention the parents)?  Another question is: Are there risks (other than temporary discomfort) to giving all these immunizations?  A third question is: Does delaying immunizations for babies reduce any risks?

Let’s take these questions one at a time.

Vaccines clearly save children’s lives, so the answer to the first question is an unqualified yes!  Most parents have never seen a case of polio, or diphtheria, or tetanus (lock jaw).  The reason is that vaccines prevent them.  These were devastating diseases that killed or paralyzed many infants and children. They have not gone away.  If the immunization rate falls, we will see them again. We already have in communities where the immunization rate has fallen below a critical level.  In times past, many children died from pneumonia caused by a class of bacteria called pneumococcus.  The pneumonia shot has virtually eliminated this disease.

I have my own story about the Hemophilus influenza vaccine (Hib).  Until this vaccine came out, I saw at least one child a year with a serious infection from this bacterium. It caused meningitis, joint infections and pneumonia.  The sickest child I ever cared for had H-flu meningitis.  Since the vaccine came out, I have never seen another case.

Rotavirus is a common cause of severe diarrhea and dehydration in infants, and some die from this.  The rotavirus vaccine prevents this disease

Some parents wonder why we give vaccines for measles, mumps, rubella (german measles) and chicken pox.  Most adults over 60 had these infections in childhood and recovered just fine. Unfortunately, lots of people did not do just fine.  Measles can cause infection of the brain and pneumonia, Many people actually died or were permanently disabled by measles. The same story holds for chicken pox.  Rubella (german measles) is a mild, self-limited illness except if a pregnant mother catches  it.  In that case it causes severe birth defects in the baby.

Another question parents often have is why we give hepatitis B vaccine to all children.  Hepatitis B is transmitted by sexual intercourse or by needle stick, but it can also be transmitted to a baby during birth.  The recommendation used to be that we gave hepatitis B vaccine only to babies of high risk mothers. That did not work very well because it was impossible to reliably identify high risk mothers.  If you know for sure that neither parent has a chance of having hepatitis B, then it is reasonable to delay this vaccine until the child is older.  The only way to be sure is for both parents to test negative for hepatitis B antibodies. Since you don’t know and cannot control what sexual experience your child will have later in life, this vaccine should at least be given before puberty.

A final question that parents have is about the COVID-19 vaccine for children. Why do we need to give the vaccine when most children have only mild disease? There are two reasons to give the COVID vaccine to babies. One reason is that although most children have only mild disease, some children get very sick and have to be hospitalized. The other reason we immunize babies and children for COVID-19 is to protect vulnerable adults that they may be exposed to. Most hospitalizations for COVID-19 now are older people and people who have other risk factors such a suppressed immune system, diabetes, COPD and other chronic diseases.

Now lets talk about risks of vaccines.  I’m not talking about mild reactions such as a little irritability, low grade fever, or mild swelling at the site of the shot. That type of reaction is fairly common and self limited.  The real question most parents have is about long term serious risks to immunizations. Here are some questions frequently asked by parents.

1. Do immunizations increase the risk that my child will get autism?  The answer is no.  There is one study often quoted by anti-vaccine groups that reported an association between childhood immunizations and autism.  It turns out that the author of the study faked a lot of his data.  It has been thoroughly discredited and in fact the journal that published it retracted it.  Several very large well designed studies that were designed to answer this question found absolutely no connection between childhood immunizations and autism.

2. Do all these immunizations overstimulate children’s immune systems and increase the risk of autoimmune diseases later in life? The answer again is no.  In order for the immune system to work properly, it is stimulated by literally thousands of environmental substances called antigens during a child’s life.  It makes antibodies against these antigens so that children develop immunities to viruses and bacteria in the environment.  The vaccine antigens represent a tiny fraction of all the antigens in the environment, certainly not enough to cause overstimulation. Studies have shown no connection between immunizations and autoimmune diseases such as multiple sclerosis, lupus, or rheumatoid arthritis

3. What about the mercury preservative in vaccines. Does that cause any long term problems?  The preservative thimersol, which does contain some mercury, has been removed from all vaccines since 1992.  There was no evidence that this caused any problems, but it is nonetheless not an issue anymore.

4. Did some children have severe reactions to the pertussis (whooping cough) vaccine?

The old pertussis vaccine was called a whole cell vaccine. It contained the entire inactivated pertussis germ. There were very rare serious reactions with this vaccine, including high fever and sometimes seizures. Now the pertussis vaccine does not contain the whole germ. It is called an acellular vaccine. Since the acellular vaccine was added to the diphtheria and tetanus vaccines (now called the DTaP vaccine), serious reactions were eliminated.

5. Can COVID-19 vaccine cause decreased fertility or other long term chronic disease?

A tiny number of adolescents who received the COVID-19 vaccine developed some inflammation of the lining around the heart. None of these children were hospitalized and all recovered completely. This did not happen when 6 month old children got the vaccine. There is no evidence whatever that COVID-19 vaccines decrease fertility in women or men. That is one of those pieces of misinformation that grow on the internet like weeds. We have seen no ill effects from the COVID-19 vaccine in infants.

6. Is there any benefit to delaying vaccines until children get older?  Once again the answer is an emphatic no.  There is no evidence of any health benefit to delaying immunizations.  All of the diseases we immunize children against are most dangerous in infancy.  Pertussis (whooping cough) and diphtheria killed many infants before we had vaccines to prevent them.  All the other diseases we immunize against have a much higher chance of causing death in infants.  If you delay your child’s immunizations, you are depending on everyone else getting immunized to protect your child.  Not only is that not fair, but in some communities the immunization rate for infants has gotten low enough that you don’t even have that protection.

Bottom Line: Immunizations for infants and children are safe and effective.  They prevent diseases that used to kill or maim many infants and children. The only downside is the discomfort of multiple shots, which can be significantly ameliorated by using combined vaccines.  Delaying vaccines until children are older is dangerous for the child and provides no health benefits.

Omicron Variant of SARS-COV-2

I will continue the series of posts on healing relationships, but I think we have enough information about the omicron variant of SARS-COV-2 to spend some time talking about it. In this post I will discuss infectivity, vaccine resistance, and some prevalent misinformation which continues to complicate rational measures to combat the virus.

Infectivity

First a little review on epidemiology. Those of you who want a more complete review can look at my previous post Epidemiology Made Simple. The potential infectivity of any virus or bacteria is described by a number called R0. R0 is the average number of other people that one infected person infects. R0 for the original SARS-COV-2 virus detected in Wuhan, China was about 2.5. That means that on average one infected person infected between two and three other people. The delta variant of SARS-COV-2 has an R0 of about 7. That means that on average one person infected with the delta variant infects 7 other people. The delta variant is almost three times as infectious as the original virus!

So far it looks like the omicron variant has an R0 of about 10. To put that in perspective, the most infectious virus that we know of is the measles virus. It has an R0 of 13. That means the omicron variant is almost as infectious as measles. That is why it is spreading so fast. Cases in the U.K. where omicron is predominant are doubling every two to three days! That makes it almost impossible to limit the spread by contact tracing.

R0 refers only to the potential infectivity of the virus in people who have no immunity. This potential infectivity can be reduced by measures that either increase immunity (such as vaccination or previous infection) and/or that limit the spread of the virus in people such as masking, social distancing and avoiding small, poorly ventilated indoor spaces.

Effectiveness of vaccines for omicron

Effectiveness of vaccines is measured two ways. First is the effectiveness of the vaccine in prevention of infection in the first place. Second and much more important is the effectiveness of the vaccine in preventing hospitalization and death.

Omicron has more than thirty mutations in the spike protein. This means that it looks very different from the original virus isolated in Wuhan. The previous definition of fully vaccinated was two immunizations. Those people who had two vaccinations had about 70% protection from infection with the delta variant, but so far in the U.K. it looks more like 10% protection from omicron infection. Protection from being sick enough to be in the hospital, though is still very good, even without a booster. Having a booster gives about 80% protection from symptomatic infection and about 99.9% protection from hospitalization and death.

Does the omicron variant cause milder disease?

It is too early to be sure about that. Hospitalization rates for people infected with the omicron variant are lower so far, but that is in countries such as the U.K. with very high vaccination rates, or like South Africa that has high numbers of people who have had COVID previously. We don’t yet know the hospitalization rate for the unvaccinated, but hospitalizations are starting to go up in the U.K. and in much of the U.S. What we can say so far is that the omicron variant does not seem to cause more severe disease, but that is all we can say at this point. Because omicron is so contagious, we will see huge increases in case numbers and therefore hospitalizations no matter what the severity of illness omicron causes.

What about children?

There have been a number of articles in the press recently about hospitalizations going up for children with COVID. While that is true, the numbers are still tiny compared to hospitalizations for adults. Children are still at substantially lower risk of symptomatic infection even with the omicron variant. That does not mean that they don’t get infected at all, just that their infections are much more likely to have no symptoms. In a recent large antibody study in Texas (more about this later) a third of the children in the study showed evidence of previous COVID. Over half of those children had no history of any symptoms at all. That is good news for the children, but bad news for adults exposed to them. It appears that infected children without symptoms could be major spreaders of COVID.

Vaccines protect children five to twelve years old as well as they protect adults. The only serious side effect for children is mild inflammation of the heart called myocarditis. This occurs in about one in one million doses, almost never requires hospitalization and goes away by itself.

There has been a great deal of misinformation about the risk of vaccination in children. A U.S. virologist, Dr Robert Malone, has posted a video claiming that the spike protein fragments created by the vaccine are toxic and cause damage to multiple organs in children. This is utterly false. Millions of children have received the Pfizer vaccine and there is not one shred of evidence that there is any organ damage other than the mild transient myocarditis that occurs in one in a million.

Is having had and recovered from COVID as good protection as having a vaccine?

There definitely is some protection from having COVID in the past. It is not as good as protection from the vaccine though, and it tends to wane more quickly than protection from the Pfizer or Moderna vaccine. In the Texas study that I mentioned earlier, called Texas Cares, the University of Texas Health Science Center recruited over 87,000 people in Texas ages 8 to 80. I was a participant in that study. Every participant filled out a survey asking about symptoms of COVID and dates of vaccinations. Then blood was drawn at a local lab at baseline and every 3 months for two more times. The survey was repeated before each blood draw.

Two antibody tests were done on each sample. One test measured the N antibody. People who were positive for N antibody had COVID at some previous time. The other test measured antibodies to the SARS-COV-2 spike protein. The spike protein antibodies are the neutralizing antibodies that protect you from severe illness with COVID. People who had only the spike protein antibody had been vaccinated but had never had COVID. The preliminary results were recently published. What they found was that spike protein antibodies in unvaccinated people with a previous infection peak at 120 days after infection and then decrease. Unvaccinated people with a previous infection overall had lower levels of spike protein antibodies than people who were vaccinated. People who had a previous infection and were vaccinated had the highest levels of spike protein antibodies.

As an example I will use my own data from this study as well as the data from a friend who had COVID but had not been vaccinated. My initial spike protein antibody level was over 300. His was 30. Three weeks after my booster of the Pfizer vaccine I went for the second blood draw. My spike protein antibodies at that blood draw were over 2,500.

This study clearly suggests that COVID vaccines give better protection than previous COVID infection and that boosters cause a big increase in neutralizing antibody. The combination of previous COVID infection and vaccination gives the best protection of all.

Should I wear a mask even if I am vaccinated and boosted?

The omicron variant is so contagious that even vaccinated and boosted people could still get infected even though that infection is likely (but not guaranteed) to be mild. My personal feeling (and the CDC recommendation) is that everyone should continue to mask indoors in public places, like grocery stores, department stores or any other public place indoors where multiple people not known to you congregate. U.S. made N-95 masks are now readily available and provide much better protection than cloth masks.

Bottom Line

The omicron variant is extremely contagious, almost as much as measles. Vaccines, especially with a booster give 80% protection from symptomatic infection and 99% protection from hospitalization and death. Children frequently get infection without symptoms and may serve to spread infection to others. Vaccinating children five to twelve is safe and effective. Having had a COVID infection in the past gives some protection but is less than protection from vaccines. Because omicron is so contagious N-95 masks should be worn in indoor public places regardless of vaccination status.

Misinformation about SARS-COV-2 and COVID-19 – Vaccine Misinformation

Introduction

In this post and the ones that follow I will try to accomplish several goals. I have been fielding a lot of requests to comment on misinformation about COVID-19. This misinformation falls into several categories, so the first thing I will do is to detail each one of these, explain why they are not true, and give the correct information. It will be impossible to respond to all the misinformation out there, because it proliferates sort of like weeds in a garden. A second goal of these posts will be to discuss how misinformation proliferates, primarily on social media. The third goal will be to provide some reliable sources of information that can always be trusted. Here goes!

Misinformation about vaccines

Vaccine Misinformation 1. The new vaccines (mRNA vaccines) are not true vaccines because they cause the body to make components of the virus rather than making fragments of the virus in a lab. mRNA vaccines are gene therapy and permanemtly alter your DNA.

First lets talk about the definition of a vaccine. A vaccine is anything that causes immunity to a disease other than being infected with the disease itself.

There can be many ways to do this. One way is to make a weakened form of the virus or bacteria and actually infect people with it. This is called a live attenuated vaccine. Measles vaccine and smallpox vaccine are examples of this. A more common method today is to use a piece of the virus or bacteria that cannot reproduce, so it can’t cause infection. This is called an inactivated vaccine. The inactivated piece of virus or bacterium causes the immune system to make antibodies against the fragment of the virus or bacterium. This allows the immune system to immediately recognize infection with the live virus or bacterium and destroy it before it becomes established in the body.

The old way to make inactivated vaccines required being able to grow the virus in the lab, figure out which part would stimulate the immune system, make lots of copies of that part, and then inject it into people. This was a very time consuming process. The shortest time to develop a vaccine like this was the mumps vaccine, and that took 10 years.

New technology allows us to quickly figure out the entire genetic sequence of the virus. The coronavirus, SARS-COV-2, happens to have a sequence of only RNA, not DNA. In a normal cell, RNA is a “messenger” from the DNA in the nucleus of the cell. The RNA actually makes the proteins that the cell needs. The RNA from SARS-COV-2 takes over the cell machinery and makes viral proteins and more viral RNA that assemble themselves into thousands of new virus particles. The cell eventually ruptures and dies, releasing the thousands of virus particles that go on to infect other cells and repeat the process.

The genius of the messenger RNA (mRNA) vaccines is to use the way the virus RNA makes proteins against it. By injecting only a piece of viral RNA, the muscle cells near the injection site take up the RNA and make thousands of copies of one of the virus proteins, called the spike protein. Since the whole viral RNA is not there, the whole virus can’t be made and no cells can be infected. The immune system makes antibodies against the spike protein made by those muscle cells. Instead of the laborious and time consuming process of making pieces of viral protein in a lab, the body does all the work using the fragment of viral RNA to make the protein that causes immunity. The DNA in the cell is never touched or altered, so this is not gene therapy. Furthermore, the fragment of viral RNA used in the mRNA vaccines is very unstable and falls apart soon after it causes the muscle cells to make copies of the spike protein.

Thus, by the definition of a vaccine mRNA vaccines are true vaccines. They cannot cause infection. They never affect DNA, so therefore are not gene therapy. They fall apart in a few hours. They have been shown to be very safe and effective at creating immunity and preventing illness from COVID-19.

Vaccine Misinformation 2. mRNA vaccines insert nano-computers into your body that can track you

This is probably a misunderstanding of the fact the the mRNA vaccine is enclosed in a little lipid (fat) particle to keep it from being immediately degraded by the body’s enzymes. These little fat globules are very small, so they are called nano particles. There are no computers, nano or otherwise in the mRNA vaccines.

Vaccine Misinformation 3. mRNA vaccines cause infertility

mRNA vaccines are only absorbed by muscle cells near the injection site. They do not circulate in the bloodstream and cannot possibly affect any part of the reproductive system in men or women.

Vaccine Misinformation 4. Covid-19 is a mild disease and side effects from vaccine are worse than the disease.

Eighty percent of people who get COVID-19 have relatively mild symptoms or no symptoms and recover completely. That leaves 20% (two out of every 10 people) who get serious disease many requiring hospitalization. Even if the overall death rate is only 1%, that is 10 times the death rate from influenza. At this point in the pandemic, COVID-19 is the leading cause of death in the United States. Serious side effects from the COVID vaccines are extremely rare. About 1 person in a million gets a severe allergic reaction called anaphylaxis. This always occurs in the first 20 minutes after administering the vaccine and is easily treated with an epinephrine shot. Mild symptoms are common including pain at the injection site, low grade fever, muscle aches, and fatigue. These almost always disappear within 24 to 48 hours.

COVID-19 is a serious, life threatening disease for two out of 10 people that get it. Vaccine side effects are common but mild and self-limited. Serious side effects are very rare and easily treated.

In the next post I will discuss misinformation about mask wearing, the origin of the virus, as well as a few common miscellaneous pieces of misinformation.

SARS-COV-2 Vaccine Update

In a previous post about when we might expect an effective vaccine for SARS-COV-2, I said it would be unlikely that a vaccine would complete phase 3 trials and be approved by early 2021. I love being wrong about that prediction! There are three vaccines that have been shown to be highly effective in phase 3 trials, and at least two of them are likely to be approved before the end of 2020. The third one will likely be approved within the next month or two. Each vaccine requires two doses and each has certain advantages and disadvantages. I will briefly describe those for each of the three vaccines below.

Pfizer-BioNtech vaccine

This vaccine was developed by a collaboration between a U.S. pharmaceutical company, Pfizer, and a German biotech company, BioNtech. It uses a technology that has never been used in a licensed vaccine before called mRNA (messenger RNA).

Traditional vaccines require growing the virus in tissue culture and then breaking down the virus into components that will stimulate the immune system to make antibodies. It is a very labor intensive process to make these viral components, and they have to be intensely purified to make them safe and effective.

Messenger RNA that codes for certain SARS-COV-2 proteins can be chemically synthesized in large quantities. When injected into the upper arm, these mRNA molecules are absorbed into muscle cells, and then the muscle cells begin to make the SARS-COV-2 spike proteins. The immune system recognizes these as foreign invaders and develops antibodies against them. The genius of this approach is that the body manufactures the viral components itself rather than the labor intensive process for traditional vaccines.

One problem with this approach is that mRNA molecules are very fragile and easily fall apart. The Pfizer-BioNtech vaccine must be stored at -94 degrees. This requires a special freezer. It will be a challenge to distribute this vaccine to a large number of people, particularly in the developing world where such freezers are expensive and unavailable

Data from phase 3 trials show an efficacy of 90%. That means that that there were nine infections in the people who got the placebo vaccine for every one infection in the people who got the real vaccine. That is extraordinary. The flu vaccine, for example has only about 50% efficacy.

Moderna vaccine

This vaccine was developed by a U.S. pharmaceutical company based in Massachusetts. It is also an mRNA vaccine and also has an efficacy of 90%. Moderna used a special trick to avoid having to use super cold storage required by the Pfizer-BioNtech vaccine. They enclosed the mRNA molecules inside little lipid (fat) membranes. This makes the Moderna vaccine more stable so that it can be stored at normal freezer temperatures of zero degrees.

Oxford-AstraZeneca vaccine

This vaccine was developed by the British pharmaceutical company, Oxford and will be manufactured by the U.S. pharmaceutical company, AstraZeneca. Rather than injecting mRNA directly, the company used a cold virus isolated from Chimpanzees. They deleted 20% of the virus DNA, so that it is unable to reproduce inside the human body. They replaced that 20% with genes that manufacture the SARS-COV-2 spike protein. The virus enters the human cells and then the cells manufacture the spike protein. Once again, the immune system recognizes this spike protein as a foreign invader and makes antibodies against it.

The efficacy data for this vaccine is a little puzzling. Because of a manufacturing error, AstraZeneca made some vials that contained only a half dose of the vaccine. People who got the half dose first and then the full dose for the second shot showed a higher efficacy (90%) than those who got two full doses (70%). Moderna and AstraZeneca will have to add more people to their phase 3 trial to resolve this issue. This will delay the application for approval by a month or two. A huge advantage of this vaccine is that it can be stored at refrigerator temperatures.

Side Effects

Side effects in the phase 3 trials were not common, but did include fever, muscle aching, headache and fatigue. These symptoms only lasted a day or two and then resolved completely. There have been no serious or long term side effects reported with any of the three vaccines.

Length of Protection

Because this a novel virus that has been circulating in humans for less than a year, we do not know how long immunity will last. Hopefully it will be at least a year, but at this point that is unknown.

Will vaccines keep me from getting infected and passing the virus on to others?

The only thing that was tested in the phase 3 trials was prevention of symptomatic illness. It is possible that vaccinated people are still susceptible to asymptomatic infection and might still transmit the virus to others. Until this question can be answered, people who receive the vaccine should still practice masking and social distancing.

When will these vaccines be available?

The logistical challenge of manufacturing and distributing any of these vaccines will be daunting. None of these vaccines will likely be available to the general public before this spring or summer.

Should I take a vaccine when it is available and which one?

All three of these vaccines have had rigorous evaluation for efficacy and safety, and the FDA will review all these data independently before approving them. I would strongly recommend taking any of these vaccines once they are approved by the FDA. I certainly intend to do so,

SARS-COV-2 Vaccines: Hype vs Reality

There have been predictions by the Trump administration and by some news media as well that it may be possible to have an effective preventive vaccine for the SARS-COV-2 virus by this fall. Every even slightly positive report of phase 1 and phase 2 trials have been breathlessly reported in the media. The purpose of this post is to give some reasonable estimates of when and if there could be an effective and safe vaccine for prevention of SARS-COV-2.

How vaccines are tested and developed

Exploratory stage

In this stage academic and federally funded scientists identify antigens (molecules that stimulate the immune system) that might help or prevent a disease such as COVID-19. This stage normally takes two to four years, but because of the tremendous financial resources and number of scientists involved in the exploratory stage, there are many potential vaccine antigen candidates already identified. In fact there are currently 165 vaccine candidates who have completed the exploratory phase.

Animal Trials

Vaccine candidates are often tested in animal models. If the vaccine protects animals from infection then it is more likely to lead to human trials. Vaccine protection in animals though, does not mean the vaccine will work or will be safe in humans. The two coronavirus vaccines that are farthest along in development, the one by Moderna and the one by Oxford have shown protection from pneumonia in mice and monkeys, but the noses of the animals showed just as much virus as monkeys that were not vaccinated.

Phase 1 Trials

In phase 1 trials, a small group of people are given a vaccine to see if the vaccine induces antibodies and if there are any adverse reactions. These involve only 15-20 people. The production of antibodies does not prove the vaccine will be effecting in preventing or reducing severity of infection. Twenty eight coronavirus vaccines have completed phase 1 trials.

Phase 2 Trials

In phase 2 trials the vaccine is given to hundreds of healthy people in different age and risk groups to see if the vaccine acts differently in different groups of people. Phase 2 trials provide more information about antibody production, but do not provide evidence about the effectiveness of the vaccine in the real world. Fifteen vaccines have completed or are currently in phase 2 trials.

Phase 3 Trials

In phase 3 trials, the vaccine is given to thousands of people. Half the people get a placebo injection while the other half get the vaccine injection. Both groups are followed over time to see how many in each group get infection and how severe the infection is. Each group is also monitored for side effects. A vaccine that is safe and effective will show decreased infection in the vaccine group compared to the control group and side effects in the vaccine group should be minimal and not serious. To count as effective, a vaccine would need to be at least as effective as the flu vaccine, which usually has about 50% protection. Nine vaccine candidates are in phase 3 trials. There are no shortcuts for phase 3 trials. Depending on the prevalence of the virus in the population being tested, phase 3 trials are likely to last from 1 to 4 years.

Chances of success

The success rate for vaccines that make it to phase 3 trials is low, around 30%. The good news is that there are a very large number of vaccines in various stages of testing. It is likely that at least two or three of these will turn out to be safe and effective. There is no guarantee that any of the vaccine currently in phase 3 trials will turn out to be safe and effective, and most will likely fail. Although it is possible that we will have a safe and effective vaccine by early in 2021, it is very unlikely.

Risks of emergency approval of vaccines

Russia and China have given emergency approval of vaccines that have not yet completed phase 3 trials. This is very dangerous. The bar for safety for giving a vaccine to millions of healthy people is very high. Short cutting the phase 3 trials has the potential to harm thousands of people with a vaccine that we don’t even know will be effective.

Hopefully the U.S. will not follow suit and the FDA will not approve a vaccine until phase 3 trials are completed and a vaccine is shown to be safe and effective.