Are childhood vaccines grounded in evidence?

In a hearing before the Senate HELP committee, RFK Jr. claimed that most childhood vaccines were not tested for safety using placebo trials before being approved and that the government only recently started using evidence-based medicine for vaccines.

In the clip above, Kennedy claims 1) vaccine experts at the CDC and FDA haven’t used “evidence-based medicine” until recently 2) vaccines are exempt from pre-licensing safety testing, 3) the only vaccine tested in a placebo-controlled trial was the COVID vaccine and 4) that children receive 76 of these “untested” shots.

Evidence-based medicine means using the best available data and research to make medical decisions. This has been part of vaccine development for decades. The committees at the CDC and FDA are made up of doctors, scientists, and public health experts who look at all the scientific data before making decisions about vaccines. These groups don’t just guess—they follow strict rules and look at all the evidence before recommending a vaccine for use.

Vaccines are tested very carefully before they are approved; the process is clearly laid out by the CDC and FDA.  First, they go through lab and animal testing. Then, they go through three stages of human clinical trials and those results are thoroughly reviewed before the vaccines are considered for approvals.

In these trials, thousands of volunteers are given either the vaccine or something else, like a placebo or a different vaccine, so researchers can compare the results. Even if the placebo is not always just saline (an “inert” placebo), the comparison is still valid. Scientists compare rates of illness and side effects between the two groups to see how well the vaccine works and whether it causes any problems.

A common misconception is that a placebo must be an inert substance, but that’s not always the case. If there is an adjuvant that has been tested for safety in the past, the placebo might include the adjuvant to keep the trial arms as identical as possible between the vaccine and the placebo. Additionally, in the cases of new vaccines, if there is a vaccine that already exists, that can be used as a placebo against a new, possibly improved vaccine, since you’re testing whether the new treatment works better than the old one.

Saline-placebo-controlled trials are conducted for many vaccines to assess both safety and efficacy:

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

There are currently 22 diseases on the childhood vaccine schedule that children are protected against. Some of them have multiple doses of vaccine, but protection against some of the diseases are combined together so that you are getting protection against 4 or even 6 diseases in one shot.  For example, Vaxelis is a vaccine that protects against 6 diseases over a course of 3 doses, yet opponents would count that as having received 24 shots.

In short, vaccines are among the most carefully tested medical products we have. They undergo long, detailed studies before being used in people, and scientists continue to monitor their safety even after they are approved.