Immunizations

Pertussis (Whooping Cough): Resurgence of a Deadly Disease

A recent article in the journal Pediatrics reported a surge in cases of pertussis, commonly known as whooping cough. Unfortunately the article is only available to subscribers to the journal. Here is a link to a description of that article in a medical news service called Medscape. Pertussis is a bad disease. See below.

History of pertussis

Pertussis is caused by a bacterium, Bordatella Pertussis. Prior to the advent of pertussis vaccines, pertussis was one of the leading US causes of death of children under 5 years of age. There were over 200,00 cases and 9000 childhood deaths in the US from pertussis every year (a rate of 4.5 deaths per thousand children). Pertussis was especially lethal in infants, and was probably the leading cause of death in this age group. Worldwide, pertussis prior to vaccines was just as bad as in the US or worse. Worldwide there were 24.1 million cases and 160,700 deaths in children under five every year.

Epidemiology of pertussis

In un-immunized people pertussis is extremely infectious, almost as much as measles. One infected person on average infects 12-18 other people. In adolescents and adults pertussis is unlikely to cause death or hospitalization, but it is an extremely unpleasant disease. Older children and adults have paroxysms of coughing, followed by a loud, wheezing inspiration (the whoop of whooping cough). These symptoms can last for weeks or months. The coughing is sometimes so severe that people break ribs or develop hernias. Treatment with antibiotics is used to prevent transmission. Antibiotics are also given to contacts to prevent them from getting infected. Antibiotics do not have any effect on the length or severity of the disease. Those who have symptomatic pertussis just have to wait for it to go away. Here is an audio file of a child with pertussis. You should listen to it realize what a severe disease pertussis is. Let me warn you that it is distressing to listen to.

Pertussis vaccines

Whole cell pertussis vaccines

Whole cell pertussis vaccine combined with vaccines for tetanus and diphtheria was widely introduced and given to infants and children in the 1940’s. This was a highly effective vaccine. It not only prevented disease, but also prevented colonization and therefore stopped transmission of pertussis. It reduced the cases of pertussis by 75%. Unfortunately, the whole cell vaccine had rare but concerning side effects.These iincluded persistent crying, febrile seizures and hypotonic-hypoeresponive episodes (HHE). Children with HHE had sudden onset of reduced muscle tone, decreased responsiveness to verbal or other stimuli, and change in skin color (pallor or cyanosis) that occurred shortly after vaccination. These adverse events, though temporary were obviously distressing to parents. There were also rare cases of encephalopathy (Inflammation of the brain) that caused permanent disability. These cases were so rare that it was impossible to know whether these permanent disabilities were caused by the vaccine, or were simply associated but not causal. Controversy over whether the vaccine had any role in these cases continues even today.

Acellular pertussis vaccine

Because of the rare but distressing side effects of whole cell pertussis vaccine, a new vaccine was developed that had components of the pertussis bacterium, but not whole cells. This was called the acellular vaccine. This acellular vaccine had far fewer and milder adverse reactions than the whole cell vaccine. The combination vaccine is abbreviated DTaP (diptheria-tetanus-acellular pertussis). This is the vaccine used for children today. Unfortunately the acellular pertussis vaccine is less effective than the previous whole cell vaccine. It does prevent children from getting ill with pertussis, but it does not prevent colonization of the nose and throat. Children who are colonized in this way are not sick, but they are infectious and can pass on the virus to other children and adults. This keeps the bordatella pertussis bacteria circulating in communities.

Waning Immunity

Neither the whole cell nor the acellular vaccine provides lifetime immunity, unlike the Measles-Mumps-Rubella vaccines, which do provide lifetime immunity. Even people who have pertussis do not get lifetime immunity. Immunity from vaccines and infection wane over time. It appears that the acellular pertussis vaccine gives good protection from getting sick from pertussis for about 4 years, and starts to wane after that. The result is that we still see pertussis even in fully immunized children and adults starting about 5 years after the last routine immunization, which occurs at between 4 and 6 years of age. A booster TDaP is also recommended at around 12 years of age. This means that the most vulnerable children, that is children 5 or under are protected from getting ill from pertussis. Infants below 2 months of age (too early for vaccination) are protected by the recommendation that all pregnant women get a booster TDaP vaccine in the third trimester of every pregnancy. Anyone who is going to have extended contact with an infant under 2 months should also get a booster TDaP.

Risk of resurgence of severe pertussis

Bordatella pertussis continues to circulate in communities because of colonization of immunized children. Resistance to vaccinating children with DTap can quickly cause a resurgence of pertussis in infants and young children. This would be disastrous and is already happening. In 2024, there were 35,435 documented cases of pertussis across the U.S., including 655 in Colorado. That was a huge jump over the 7063 cases in all of 2023. Large states, including New York and California, logged high numbers of pertussis infections in 2024. So did some less-populated states like Idaho, Washington and Oregon, each of which reported more than 1,000 cases of pertussis. There were 10 deaths from pertussis in 2024. Cases are on track to be even higher in 2025.

Research on new pertussis vaccines

The search is on for a new pertussis vaccine that prevents colonization but that also does not cause the distressing side effects that happened with the whole cell pertussis vaccine. The best candidate at the moment is a live vaccine that has been genetically modified to eliminate the toxins produced by the bacterium. If and when approved this vaccine will be administered nasally. In rhesus monkeys it prevented colonization with bordatella pertussis and had no significant side effects. It is currently in phase 3 trials in humans.

Bottom Line

Pertussis is a serious disease and is life threatening to infants and young children. The severity and duration of pertussis are not affected by antibiotics that are given to limit the spread of the disease. The only effective treatment of pertussis is prevention through immunization. Acellular pertussis vaccine is much safer but also less effective than the old whole cell vaccine. It allows bordatella pertussis to continue to circulate in communities. Resistance to immunization of children has led to a marked increase in serious pertussis infections in 2024 with 10 deaths reported. Pertussis cases are on track to be even higher in 2025. A promising new attenuated live pertussis vaccine is in phase 3 trials and may soon be approved assuming research funding is not withheld by the Trump administration.

Autism: Is There An Epidemic?

HHS Secretary Robert F. Kennedy Jr has declared that there is an epidemic of autism and that there must be some environmental toxin that is causing it. The evidence says otherwise. I will review the evidence in this post.

Increased diagnosis of autism

There is no question that autism is being diagnosed more frequently than in the past. According to the CDC, in 2000 the prevalence of autism was 7 per thousand 8 year old’s and by 2024 was 32 per thousand, a 4.5 times increase.

Evolution of diagnostic criteria for autism

Up until 1980, autism was considered a form of schizophrenia in children. It was thought to be rare, probably because many of these children were institutionalized. Over the various versions of the DSM (Diagnostic and Statistical Manual) criteria over the years, the criteria to diagnose autism have been constantly expanded, resulting in a progressive increase in the frequency of the diagnosis of autism. In the most recent version of the DSM all the subcategories of autism including Asperger’s disease were combined into one diagnosis – autism spectrum disorder. This resulted in a marked increase in the diagnosis of autism, because it included all the less severe forms of autism. There is an excellent description of this evolution on the Arizona Autism United blog: How the Autism Diagnosis Has Evolved Over Time.

Has the frequency of severe autism increased?

Severe or profound autism includes children who have no or little speech, are intellectually disabled, and some have challenging behavior that interferes with safety and well being. According to the CDC, people with severe autism make up about 26% of people with autism. Kennedy says that severe autism has markedly increased. According to Christine Ladd-Acosta, who is the vice director of the Wendy Klag Center for Autism and Developmental Disabilities, the data show that severe or profound autism has increased little or none in the last 10 years. Maureen Durkin, another well known autism researcher, divided autism cases up into different buckets. She found that severe autism has not increased at all, and in fact has decreased a little.

Screening for autism spectrum disorder

The American Academy of Pediatrics began recommending screening children for autism spectrum disorder in 2006. Screening is recommended at well child visits. There is some controversy about the benefits of screening children with no symptoms, but it is clear that screening has increased the diagnosis of autism spectrum disorder, especially milder forms of autism. Screening has also resulted in earlier diagnosis of children with more severe autism. Earlier intervention improves the outcomes in these children.

Causes of Autism Spectrum Disorder

Genetic Causes

Multiple studies including identical twin studies have shown the cause of 80% of autism spectrum disorder cases are genetic. Here is a link to an NIH article that summarizes these studies. Genetic causes are both hereditary and caused by genetic mutations.

Environmental causes

There are certain environmental factors associated with slightly increased risk of autism spectrum disorder. All of these factors account for a very small increase in the incidence of autism spectrum disorder, each less than 1%.

Advanced parental age
Prenatal exposure to air pollution or certain pesticides
Maternal obesity, diabetes or immune system disorders
Extreme prematurity or very low birth weight
Birth complications leading to periods of oxygen deprivation to the baby’s brain

Do childhood vaccines cause autism spectrum disorder?

The answer to this is a definite no. Multiple large well designed studies have shown no association of vaccines, or any component of vaccines including thimersal and aluminum that have any association with autism spectrum disorder. Here is a link to an article from the CDC summarizing these studies.

Does taking Tylenol (acetaminophen) during pregnancy cause autism?

Once again the answer is no. There were a few small studies that showed an association of acetaminophen during pregnancy and development of autism spectrum disorder. Larger, better designed studies have shown no association of acetaminophen use during pregnancy and subsequent development of autism spectrum disorder in children born from those pregnancies.

Autism spectrum as neurodiversity

Many people with milder forms of autism spectrum are fully functional and live independently. They view themselves as on a spectrum of neurodiversity rather than having a disorder. Here is a link to an article from Autism Speaks describing the idea of neurodiversity.

Bottom Line

The increase in the incidence of autism spectrum disorder is almost entirely due to increased diagnosis and increased awareness. The cause of 80% of autism spectrum disorder is genetic. There are a few environmental causes that have increased over time, but these account for only a tiny portion of the increase. There are many well designed studies that show that vaccines do not cause autism spectrum disorder. There are also similar large well designed studies that show that taking acetaminophen during pregnancy does not cause autism spectrum disorder in the babies born from those pregnancies.

Many people on the autism spectrum are fully functional and live independently. They view themselves as people with neurodiversity rather than people with a medical disorder.

There is a very good podcast called Science Versus that reviews all of the evidence that I have outlined above. It is worth listening to. Here is a link to the transcript of the podcast. You can listen to the episode on your normal podcast app. The show notes for the episode has all the references that are used in the episode.

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.

Longevity – Health Span vs Life Span

Longevity is the newest health buzzword. There are an increasing number of so-called longevity experts. They say, just read my book and follow my instructions and you can live past 100 years. Some of these “experts” focus on health span. They say follow my instructions and you will stay healthy and die suddenly at an advanced age. As of 4/21/2024 there are 34 books on longevity listed on Amazon.

In this post I will do my best to distinguish the hype from the science with regard to living a long and healthy life.

Hype

Calorie restricted diets – Some people have extrapolated mouse and rat experiments that show that animals fed restricted calorie diets live a lot longer than animals fed a normal diet. There is not one shred of evidence that this works with humans, and is more likely to lead to diseases of malnourishment.
Nutrtional supplements – Recommendations range from vitamins, to protein powder, to collagen powder, to herbal preparations, to encapsulated fruits and vegetables. There is absolutely no evidence that any of these things or any other supplements including multivitamins work to extend your life. Anecdotal reports of feeling better on these supplements are almost certainly a placebo effect
Anti-aging medicines – reservetrol, metformin, rapamycin have all been shown to prolong life in some experimental animals. In humans Metformin and reservetrol decrease the ability to exercise and rapamycin suppresses the immune system. There is no evidence whatever that these compounds increase life or health span in humans.
Extensive lab tests – Other than lipid (cholesterol) tests, there is no evidence that otherwise healthy non-obese people benefit from any blood tests. More about screening tests later.
Imaging tests – One of the most popular longevity “experts” ,Dr. Peter Attia, recommends full body MRI scans for his patients. Imaging tests in people who have no symptoms are much more likely to lead to over diagnosis and unnecessary treatment than to find things that really need to be treated,
Very intense exercise regimens – The only thing very intense exercise regimens accomplish that moderate exercise regimens do not is that the intense regimens are more likely to cause injury.

Science

Genetics

Up until into the 80’s, lifestyle is the major contributor to healthy aging. There are some people, however who remain healthy well into their 90’s and a few to past 100. Genetics is the main contributor to these “super centenarians.” There is not a single or even a few aging genes. Super aging is caused by hundreds of genetic variants called SNP’s (single nucleotide polymorphisms). We cannot alter our genes (yet), so there are no lifestyle changes you can make in order to live to 100 if you don’t have the rare combination of all these genetic variants.

That is not to say that lifestyle is not important to healthy aging. In the US, the average person’s last birthday in good health is age 65! Lifestyle changes will almost certainly help you do better than that.

Exercise

Regular exercise decreases your risk of chronic disease and therefore increases your chance of living healthier longer. To accomplish the maximum health benefit the CDC recommends 150 minutes of moderate exercise per week. Brisk walking or cycling at a moderate pace on level ground would qualify. If you choose high intensity exercise like jogging or running or high intensity cycling, you only need to do 75 minutes a week according to the CDC. The CDC also recommends activity to strengthen your muscles two days a week. For a population of adults doing this exercise regimen the risk of death is decreased by 17%. This regimen decreases the risk of heart disease, diabetes, certain cancers and decreases the risk of hospitalization or death from infectious diseases like COVID, flu and pneumonia. This regimen also increases bone and muscle strength and thus decreases the risk of falls and fractures. This exercise regimen also helps maintain a healthy weight.

Any amount of walking or activity decreases risk somewhat. The CDC recommended regimen decreases risk the most.

Nutrition

Eat mostly unprocessed foods and avoid ultra-processed foods. The best way to identify ultra-processed foods is to look at the ingredients label. If there are more than four ingredients, and/or if there are some you don’t recognize, then put that food back on the shelf. It is best to keep nutrition advice simple. The most concise recommendation I know comes from author Michael Pollan. “Eat food (food is anything your grandmother would have recognized as food), not too much, mostly plants.” I can’t do much better than that. Most of the evidence about the beneficial effects of good nutrition come from studies of the Mediterranean style diet. The Mediterranean diet adheres to Michal Pollan’s advice. It has lots of fruits, vegetables, fish, olive oil and very little meat. Adherence to this type of diet showed a 46% increase in living healthfully until 70 or greater.

Social Connectedness

The CDC defines social connectedness as the degree to which people have and perceive a desired number, quality, and diversity of relationships that create a sense of belonging, and being cared for, valued, and supported. An analysis of multiple studies showed that high social connectedness as defined above decreases the risk of premature death by 50%! High social connectedness also decreases the risk of heart disease, stroke and dementia.

Social Determinants of Health

The main reason that the US average health span is 65 years is the tremendous inequity of resources in the US. People who live in substandard housing (or no housing at all) do not have the opportunity or resources to do all of the things above that tend to extend life. That is why life expectancy at birth is related to zip code more than any other factor. My feeling is that we should expend our resources working on improving health equity, which will increase both life and health span for everyone rather than focusing on helping wealthy people live to 100.

Screening Tests

There are a few screening tests recommended by the US Preventive Care Task Force for healthy people. These tests are meant to find disease, especially cancer early so it can be more successfully treated and thus prolong healthy life. The absolute risk reduction of death for these tests is small, most around 1%, but that ends up saving a lot of people when you apply it to the whole US population. The recommended screening tests are listed below.

Mammograms for women beginning at age 50. Recommended every two years. Absolute risk reduction about 1%.
Pap Smears beginning at age 21 every 3 years through age 29 and then every 5 years from age 30 to 65. The absolute death risk reduction is .0009%, which means your would need to do pap smears on 11140 women to prevent one death from cervical cancer.
Colorectal cancer screening. There are three different tests: colonoscopy, the most invasive (recommended every 10 years), Cologuard (a stool sent to a lab in a box recommended every 3 years) and fecal immunochemical test (done on a stool sample and either tested at home or sent to lab recommended every year). All three tests reduce deaths from colon cancer with an absolute risk reduction of around 0.6%. Only colonoscopy can prevent some cancers by removing precancerous polyps.

Vaccines

There is no question that vaccines save lives by preventing some serious life threatening diseases, or making them less severe. Vaccines are especially important for infants and children, who are most at risk from the infectious diseases prevented by vaccines. Childhood vaccines prevent diptheria, whooping cough, tetanus, measles, mumps, rubella, polio, rotavirus (which causes severe diarrhea and dehydration in infants), hemophilus influenza (which caused joint infections and meningitis), hepatitis b, RSV (which causes severe respiratory illness), pneumonia caused by strep (the most common kind of bacterial pnuemonia), COVID (also for adults), meningitis, chicken pox, and HPV (the virus that causes cervical cancer in women).

Adults can get any of these vaccines, but also a vaccine to prevent shingles.

Bottom Line

Living in good health to past 100 depends on genetics, not lifestyle. Many things recommended by so called longevity experts do nothing to prolong life and may increase risk. There are a number of lifestyle changes including exercise, good nutrition, social connectedness, certain screening tests and vaccines that increase you chances of remaining healthy well into your eighties. The main cause of early death in the US is poverty, homelessness and systemic racism. Addressing these inequities is a lot more important than helping wealthy people try to live to 100.

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.