Here are two articles from vaccine experts who show that HHS Secretary Robert F. Kennedy Jr. doesn't know what he's talking about.
I’m a physician who has looked at hundreds of studies of vaccine safety, and here’s some of what RFK Jr. gets wrong
Many of these statements are factually incorrect. For example, in a newscast aired on June 12, 2025, Kennedy told Fox News viewers that 97% of federal vaccine advisers are on the take. In the same interview, he also claimed that children receive 92 mandatory shots. He has also widely claimed that only COVID-19 vaccines, not other vaccines in use by both children and adults, were ever tested against placebos and that “nobody has any idea” how safe routine immunizations are.
As an infectious disease physician who curates an open database of hundreds of controlled vaccine trials involving over 6 million participants, I am intimately familiar with the decades of research on vaccine safety. I believe it is important to correct the record – especially because these statements come from the official who now oversees the agencies charged with protecting Americans’ health.
Do children really receive 92 mandatory shots?
In 1986, the childhood vaccine schedule contained about 11 doses protecting against seven diseases. Today, it includes roughly 50 injections covering 16 diseases. State school entry laws typically require 30 to 32 shots across 10 to 12 diseases. No state mandates COVID-19 vaccination. Where Kennedy’s “92 mandatory shots” figure comes from is unclear, but the actual number is significantly lower.
From a safety standpoint, the more important question is whether today’s schedule with additional vaccines might be too taxing for children’s immune systems. It isn’t, because as vaccine technology improved over the past several decades, the number of antigens in each vaccine dose is much lower than before.
Antigens are the molecules in vaccines that trigger a response from the immune system, training it to identify the specific pathogen. Some vaccines contain a minute amount of aluminum salt that serves as an adjuvant – a helper ingredient that improves the quality and staying power of the immune response, so each dose can protect with less antigen.
Those 11 doses in 1986 delivered more than 3,000 antigens and 1.5 milligrams of aluminum over 18 years. Today’s complete schedule delivers roughly 165 antigens – which is a 95% reduction – and 5-6 milligrams of aluminum in the same time frame. A single smallpox inoculation in 1900 exposed a child to more antigens than today’s complete series.
Since 1986, the United States has introduced vaccines against Haemophilus influenzae type b, hepatitis A and B, chickenpox, pneumococcal disease, rotavirus and human papillomavirus. Each addition represents a life-saving advance.
The incidence of Haemophilus influenzae type b, a bacterial infection that can cause pneumonia, meningitis and other severe diseases, has dropped by 99% in infants. Pediatric hepatitis infections are down more than 90%, and chickenpox hospitalizations are down about 90%. The Centers for Disease Control and Prevention estimates that vaccinating children born from 1994 to 2023 will avert 508 million illnesses and 1,129,000 premature deaths.
Placebo testing for vaccines
Kennedy has asserted that only COVID-19 vaccines have undergone rigorous safety trials in which they were tested against placebos. This is categorically wrong.
Of the 378 controlled trials in our database, 195 compared volunteers’ response to a vaccine with their response to a placebo. Of those, 159 gave volunteers only a salt water solution or another inert substance. Another 36 gave them just the adjuvant without any viral or bacterial material, as a way to see whether there were side effects from the antigen itself or the injection. Every routine childhood vaccine antigen appears in at least one such study.
The 1954 Salk polio trial, one of the largest clinical trials in medical history, enrolled more than 600,000 children and tested the vaccine by comparing it with a salt water control. Similar trials, which used a substance that has no biological effect as a control, were used to test Haemophilus influenzae type b, pneumococcal, rotavirus, influenza and HPV vaccines.
Once an effective vaccine exists, ethics boards require new versions be compared against that licensed standard because withholding proven protection from children would be unethical.
How unknown is the safety of widely used vaccines?
Kennedy has insisted on multiple occasions that “nobody has any idea” about vaccine safety profiles. Of the 378 trials in our database, the vast majority published detailed safety outcomes.
Beyond trials, the U.S. operates the Vaccine Adverse Event Reporting System, the Vaccine Safety Datalink and the PRISM network to monitor hundreds of millions of doses for rare problems. The Vaccine Adverse Event Reporting System works like an open mailbox where anyone – patients, parents, clinicians – can report a post-shot problem; the Vaccine Safety Datalink analyzes anonymized electronic health records from large health care systems to spot patterns; and PRISM scans billions of insurance claims in near-real time to confirm or rule out rare safety signals.
These systems led health officials to pull the first rotavirus vaccine in 1999 after it was linked to bowel obstruction, and to restrict the Johnson & Johnson COVID-19 vaccine in 2021 after rare clotting events. Few drug classes undergo such continuous surveillance and are subject to such swift corrective action when genuine risks emerge.
The conflicts of interest claim
On June 9, Kennedy took the unprecedented step of dissolving vetted members of the Advisory Committee on Immunization Practices, the expert body that advises the CDC on national vaccine policy. He has claimed repeatedly that the vast majority of serving members of the committee – 97% – had extensive conflicts of interest because of their entanglements with the pharmaceutical industry. Kennedy bases that number on a 2009 federal audit of conflict-of-interest paperwork, but that report looked at 17 CDC advisory committees, not specifically this vaccine committee. And it found no pervasive wrongdoing – 97% of disclosure forms only contained routine paperwork mistakes, such as information in the wrong box or a missing initial, and not hidden financial ties.
Reuters examined data from Open Payments, a government website that discloses health care providers’ relationships with industry, for all 17 voting members of the committee who were dismissed. Six received no more than US$80 from drugmakers over seven years, and four had no payments at all.
The remaining seven members accepted between $4,000 and $55,000 over seven years, mostly for modest consulting or travel. In other words, just 41% of the committee received anything more than pocket change from drugmakers. Committee members must divest vaccine company stock and recuse themselves from votes involving conflicts.
A term without a meaning
Kennedy has warned that vaccines cause “immune deregulation,” a term that has no basis in immunology. Vaccines train the immune system, and the diseases they prevent are the real threats to immune function.
Measles can wipe immune memory, leaving children vulnerable to other infections for years. COVID-19 can trigger multisystem inflammatory syndrome in children. Chronic hepatitis B can cause immune-mediated organ damage. Preventing these conditions protects people from immune system damage.
Today’s vaccine panel doesn’t just prevent infections; it deters doctor visits and thereby reduces unnecessary prescriptions for “just-in-case” antibiotics. It’s one of the rare places in medicine where physicians like me now do more good with less biological burden than we did 40 years ago.
The evidence is clear and publicly available: Vaccines have dramatically reduced childhood illness, disability and death on a historic scale.
Jake Scott, Clinical Associate Professor of Infectious Diseases, Stanford University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
A preservative removed from childhood vaccines 20 years ago is still causing controversy today − a drug safety expert explains
An expert committee that advises the Centers for Disease Control and Prevention on vaccines is meeting for the first time since Health Secretary Robert F. Kennedy Jr. abruptly replaced the committee’s 17 members with eight hand-picked ones on June 11, 2025.
The committee, called the Advisory Committee on Immunization Practices, generally discusses and votes on recommendations for specific vaccines. For this meeting, taking place June 25-26, 2025, vaccines for COVID-19, human papillomavirus, influenza and other infectious diseases were on the schedule. According to an updated agenda, however, the committee is now also scheduled to hear a presentation on a chemical called thimerosal and to vote on proposed recommendations regarding its use in influenza vaccines.
Public health experts have raised concerns about the presentation, noting that anti-vaccine advocates continue to promote confusion regarding the purported health risks of thimerosal despite extensive research demonstrating its safety.
I’m a pharmacist and expert on drug information with 35 years of experience critically evaluating the safety and effectiveness of medications in clinical trials. No evidence supports the idea that thimerosal, used as a preservative in vaccines, is unsafe or carries any health risks.
What is thimerosal?
Thimerosal, also known as thiomersal, is a preservative that has been used in some drug products since the 1930s because it prevents contamination by killing microbes and preventing their growth.
In the human body, thimerosal is metabolized, or changed, to ethylmercury, an organic derivative of mercury. Studies in infants have shown that ethylmercury is quickly eliminated from the blood.
Ethylmercury is sometimes confused with methylmercury. Methylmercury is known to be toxic and is associated with many negative effects on brain development even at low exposure. Environmental researchers identified the neurotoxic effects of mercury in children in the 1970s, primarily resulting from exposure to methylmercury in fish. In the 1990s, the Environmental Protection Agency and the Food and Drug Administration established limits for maximum recommended exposure to methylmercury, especially for children, pregnant women and women of childbearing age.
Why is thimerosal controversial?
Fears about the safety of thimerosal in vaccines spread for two reasons.
First, in 1998, a now discredited report was published in a major medical journal called The Lancet. In it, a British doctor named Andrew Wakefield described eight children who developed autism after receiving the MMR vaccine, which protects against measles, mumps and rubella. However, the patients were not compared with a control group that was vaccinated, so it was impossible to draw conclusions about the vaccine’s effects. Also, the data report was later found to be falsified. And the MMR vaccine that children received in that report never contained thimerosal.
Second, the federal guidelines on exposure limits for the toxic substance methylmercury came out about the same time as the Wakefield study’s publication. During that period, autism was becoming more widely recognized as a developmental condition, and its rates of diagnosis were rising. People who believed Wakefield’s results conflated methylmercury and ethylmercury and promoted the unfounded idea that ethylmercury in vaccines from thimerosal were driving the rising rates of autism.
The Wakefield study was retracted in 2010, and Wakefield was found guilty of dishonesty and flouting ethics protocols by the U.K. General Medical Council, as well as stripped of his medical license. Subsequent studies have not shown a relationship between the MMR vaccine and autism, but despite the absence of evidence, the idea took hold and has proven difficult to dislodge.
Have scientists tested whether thimerosal is safe?
No unbiased research to date has identified toxicity caused by ethylmercury in vaccines or a link between the substance and autism or other developmental concerns – and not from lack of looking.
A 1999 review conducted by the Food and Drug Administration in response to federal guidelines on limiting mercury exposure found no evidence of harm from thimerosal as a vaccine preservative other than rare allergic reactions. Even so, as a precautionary measure in response to concerns about exposure to mercury in infants, the American Academy of Pediatrics and the U.S. Public Health Service issued a joint statement in 1999 recommending removal of thimerosal from vaccines.
At that time, just one childhood vaccine was available only in a version that contained thimerosal as an ingredient. This was a vaccine called DTP, for diphtheria, tetanus and pertussis. Other childhood vaccines were either available only in formulations without thimerosal or could be obtained in versions that did not contain it.
By 2001, U.S. manufacturers had removed thimerosal from almost all vaccines – and from all vaccines in the childhood vaccination schedule.
In 2004, the U.S. Institute of Medicine Immunization Safety Review Committee reviewed over 200 scientific studies and concluded there is no causal relationship between thimerosal-containing vaccines and autism. Additional well-conducted studies reviewed independently by the CDC and by the FDA did not find a link between thimerosal-containing vaccines and autism or neuropsychological delays.
How is thimerosal used today?
In the U.S., most vaccines are now available in single-dose vials or syringes. Thimerosal is found only in multidose vials that are used to supply vaccines for large-scale immunization efforts – specifically, in a small number of influenza vaccines. It is not added to modern childhood vaccines, and people who get a flu vaccine can avoid it by requesting a vaccine supplied in a single-dose vial or syringe.
Thimerosal is still used in vaccines in some other countries to ensure continued availability of necessary vaccines. The World Health Organization continues to affirm that there is no evidence of toxicity in infants, children or adults exposed to thimerosal-containing vaccines.
Terri Levien, Professor of Pharmacy, Washington State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
