Changes to the CDC “Vaccines and Autism” web page have people concerned that vaccines might be related to the causes of autism. Let’s talk about the facts.

The main issue with the CDC’s new statement is that it gets the scientific process backwards. Science begins with a hypothesis or a question and conducts multiple experiments to see if they can come up with the same answer over and over again. There are some important parts of this process that the new web page ignores:

1. Science cannot prove a negative. If someone asked the question “Can pigs fly?” scientists could come up with experiments to observe whether or not a pig could fly. The scientific, technical answer would probably be “Evidence does not exist to support the hypothesis that pigs can fly.” But that doesn’t mean that pigs can fly. They can’t. The statement simply accurately describes the evidence.
2. If scientists wanted to proclaim that pigs can fly, they would need to provide proof that pigs can fly. Saying that no studies say that they do not fly is not proof that they can fly. It’s only misunderstanding the science.
3. Scientists know that not all studies are good studies, and they do not need to consider or take into account poorly done studies. Let’s say someone conducted a survey by sending out a survey out via social media, asking people if they have ever seen a pig fly. This study would have a lot of problems, the least of which is who would decide to take the survey. Scientists would not need to include this study in discussions about flying pigs.

Instead of following the evidence, the rewritten CDC web page has decided it wants to frame vaccines for causing autism, so it is warping the evidence to fit that conclusion. They have violated every rule of science.

The evidence about autism:

Do pigs fly? No. Do vaccines cause autism? No. But how do we know that?

Studies show that autism is mostly caused by genetics and starts very early, even before a baby is born. The brain differences seen in people with autism begin during early development in the womb, not because of vaccines or anything that happens later.

Unfortunately, the web page misrepresents many studies we have discussed before:

• The study from Denmark looked at more than 650,000 children born between 1999 and 2010 to see if the measles-mumps-rubella (MMR) vaccine was linked to autism. It found that whether or not a child was diagnosed with autism was not at all related to them receiving or not receiving the MMR vaccine. The web page makes it sound like vaccines in Denmark are different, but Danish kids and American kids get the same MMR vaccines at very similar times.
• The IOM study states that there is “insufficient evidence” to accept or reject specific hypotheses about vaccines and autism. In systematic reviews like this, the label “insufficient evidence” does not mean a hypothesis is just as likely to be true as any other explanation. This phrase is often used because some conditions are very rare or have too few cases to study, not because researchers see warning signs or think the hypothesis might be correct.
• The IOM study clearly states: “The evidence favors rejection of a causal relationship between MMR vaccine and autism.” The MMR does not cause autism.

The web page also builds in doubt about the entire childhood vaccine schedule causing autism, suggesting that kids today get too many vaccines. But that doesn’t line up with what has actually happened with autism rates and vaccine development:

• Autism diagnoses kept increasing from 2000 to 2020, even though most major childhood vaccines were introduced back in the 1980s and 1990s, and only smaller changes were made to the schedule after 2000..
• Autism affects 1 out of every 36 children in the United States. In other countries, autism rates are about 1the same or higher, even though their vaccine schedules are different from the U.S. schedule and often include fewer shots for young children.

What’s important to know about autism:

Autism isn’t a tragedy. Autistic people deserve a world that accepts them and can accomodate them. That doesn’t mean parenting an autistic child is easy. We certainly do not do enough to support parents in general, much less parents of neurodivergent children.

Incorrectly tying vaccines to autism harms autistic people. They can be subjected to phony treatments or harmful ableism. And autistic children deserve to the protection of vaccination.

On Del Bigtree’s internet show, lawyer Aaron Siri claims that the whole childhood vaccine schedule is unsafe because, according to him, none of the vaccines were ever tested the right way with real placebo groups.

Siri says that most childhood vaccines are tested against other vaccines instead of a simple salt-water placebo. But in real life, many vaccines have been tested using saline placebos to check safety and how well they work, including:

• Rubella vaccine
• Pneumococcal vaccine
• Hib vaccines
• HPV vaccine
• The Salk Polio vaccine
• Measles vaccine
• Tdap vaccine
• COVID vaccine

Sometimes a new vaccine is compared to an older vaccine, or the placebo may have tiny amounts of things like adjuvants or stabilizers that scientists already know are safe.

The World Health Organization has rules for when using a placebo is fair and safe. It is okay to use a placebo when no good vaccine exists yet and the study could help protect people. But if a country already has a safe, effective vaccine, it is not ethical to give people a placebo instead, because that would leave them unprotected and at risk.

In videos being shared by many people, security specialist Gavin de Becker claims that vaccines (especially tetanus shots) have been secretly used to reduce women’s and men’s ability to have children as part of a supposed plan by the U.S., the WHO, and people like Bill Gates to lower the world’s population.

This idea began with a 2010 TED talk where Bill Gates said, “The world today has 6.8 billion people. That’s headed up to about nine billion. Now, if we do a really great job on new vaccines, health care, reproductive health services, we could lower that by, perhaps, 10 or 15 percent.” He was not talking about reducing the number of people on Earth. He was talking about lowering population growth rates by 10–15 percent.

Gates has explained many times that vaccines help slow population growth in developing countries because when parents know their children are likely to survive past age 5, they usually choose to have fewer children. Vaccines help children survive by protecting them from major killers like pneumonia and rotavirus.

Bangladesh is a great example of this idea. Bangladesh lowered its population growth rate from about 6.3 children per woman in 1971 to much fewer by 2004. The government worked hard on many things at once: a strong immunization program that kept children healthier, sanitation and clean-water efforts, more girls getting schooling, and family-planning work. These changes made families more confident that their children would survive, so they chose to have fewer children.

The conspiracy theory that vaccine companies are trying to secretly depopulate the world is not new, and it would be impossible to hide because huge numbers of people have worked on vaccines for decades.

In another video, RFK Jr. claims that flu shots weaken the immune system, making people more likely to get non-flu illnesses, including COVID.

RFK Jr. claims that the Pentagon proved flu shots make people more likely to get the flu or COVID, but the study he refers to actually says the opposite. The study’s conclusion clearly states that getting a flu shot did not make people more likely to catch other viruses. It also shows that the flu vaccine provides strong protection against many illnesses, including different types of flu, parainfluenza, RSV, and other non-flu viruses. The Department of Defense still requires flu vaccination because it helps keep service members healthy and prevent illness.

He also points to a claim that the flu vaccine causes 4.4 times more illness, based on a study of only 115 children. But that same study also looked at about 6,000 adults and found that vaccinated adults had fewer non-flu respiratory illnesses, not more. Anti-vaccine sources sometimes use only the parts of studies that support their message, while ignoring the rest. This is why scientists look at full datasets, not one small number taken out of context.

RFK Jr. further claims that the flu shot “enhances” coronavirus infections. But the study cited for this claim shows that the flu vaccine does not make people more likely to get COVID or get sicker from it. Instead, vaccines help protect against serious illness from respiratory viruses.