An old video featuring Jenny McCarthy and Jim Carey is again circulating. In it, they assert that the vaccine schedule tripled in 1990, causing a surge of autism.

“Too Many, Too Soon” is not a new claim, and it is a claim that has been studied. Vaccine hesitant parents often misunderstand that vaccines are tested alongside other vaccines on the current schedule to be sure they are safe and effective when given with other vaccines.

And while the vaccine schedule has increased over the decades (though not really at all over the last decade), so have the number of diseases we can prevent through vaccination and our scientific refinement of vaccines. In fact, the number of antigens in vaccines has decreased.

The reasons for the rise in autism rates are multi-faceted: changes in diagnostic criteria, increased awareness, educational changes, and lowered rates of intellectual disability account for most of the rising rates. Biological risk factors such as father’s age and premature birth could also account for a rise in some incidence of autism.

And there’s plenty of evidence that vaccines do not cause autism. Not only do the studies done to date show vaccines are not in any way linked to autism, but studies indicate disorganization of the prefrontal cortex in the brains of autistic people, linked to development in the womb. Of all the risk factors in developing autism, we know genetics looks the most likely and being vaccinated is not among them.

Finally, the vaccine schedule was reviewed by the Institute of Medicine. That committee found no safety concerns with adherence to the CDC-recommended vaccine schedule.

A video featuring RFK Jr. in August 2020 purports to show him predicting the future, as he discusses how he thought the COVID vaccine would be oversold and followed by a period of tempering expectations.

Was it prophetic to warn that the vaccine would lose effectiveness over time? Not when you understand how vaccines work.

When the COVID vaccine first came out, it had a high efficacy. Over time, the virus mutated and protection waned, so efficacy against mild disease dropped. We know that while our antibodies wane, our T cells last far longer, meaning that the virus might start replicating in our system even months after we have been vaccinated, but our memory cells will enter the fight and keep us out of the hospital and out of serious danger from the disease.

None of this was much of a prediction, given that two months before RFK Jr. recorded that video, the FDA explained that it “would expect that a COVID-19 vaccine would prevent disease or decrease its severity in at least 50% of people who are vaccinated.”

A common concern about vaccines, often exploited by anti-vaccine factions, is that they will overstimulate the immune system into developing an autoimmune disorder.

A large study from South Korea and Japan found that people who had COVID are at a higher risk of developing autoimmune rheumatic diseases (AIRD) ,such as rheumatoid arthritis and lupus, within a year after infection. However, COVID-infected patients who had prior vaccination against COVID did not show increased risk for AIRD, with the exception of patients with severe COVID.

The study, one of the largest on this topic in Asian populations, used data from millions of adults and compared those who had COVID-19 with those who had influenza or were not infected. It showed that the risk of autoimmune diseases after COVID was about 25% to 30% higher compared to those without infection. This risk dropped back to normal after a year. Vaccination prior to infection seemed to reduce the risk of developing AIRD by about half.