The Skeptics' Guide to the Universe: How to Know What's Really Real in a World Increasingly Full of Fake

by Steven Novella

Anti-vaccinationists who deny the safety and effectiveness of vaccines commonly ask for a randomized vaccinated-versus-unvaccinated study. While this may seem reasonable at first, they know such a study will never be done. They are essentially requiring a study that randomizes children to receive no vaccines at all. It’s unethical: Vaccines are already part of the standard of care because they have proven benefits. In a clinical trial you cannot randomize subjects to not receive standard treatment. They set the bar this high so they can deny the value of all other evidence that shows vaccines are safe. There are vaccinated-versus-unvaccinated studies, just not randomized, and there are many other types of studies showing the safety of vaccines. This strategy also uses special pleading. If a study shows that there is no association between the timing of vaccines and the incidence of autism or any other outcome, they’ll say that the effect is delayed or is from the vaccines the mother received while pregnant. If there’s no dose response, that’s because maximal negative effects are reached at tiny doses. If an ingredient is removed, then trace amounts are sufficient to have the negative effect, or some other ingredient is to blame. No evidence will ever be enough.