Vax Facts

The History of  Vaccines Suggests the Issue Is Simply Complicated

In the wake of this year's particularly large measles outbreak, New York State eliminated religious exemptions for vaccines for children attending public school.¹ In 2015, after a measles outbreak in California, that state required all public school children to be vaccinated whether their parents objected or not. Several other states have also tightened their policies. The goal is to vaccinate enough people to prevent an outbreak when others are exposed to the virus, a concept called herd immunity.

Some people have called on social media outlets to block sites that post so-called "anti-vaxxer" materials. Amazon has removed from its marketplace materials that it claims promote...