In a number of states, parents are allowed to opt out of legal requirements to have their children vaccinated before entering school by claiming a “personal belief” or “philosophical” exemption. These provisions have raised a great deal of concern since the Disneyland measles outbreak, including in California, where it began. Unfortunately, the blundering approach state legislators there have taken shows how direct attacks on exemptions can rally the anti-vaccine cause.

Senate Bill 277, which would eliminate the personal belief exemption, passed the Senate Health Committee on a 6-2 vote last week and heads to its second hearing in the Education Committee on Wednesday. The bill is scheduled to go through multiple committees, which is creating numerous opportunities for opponents to promote misinformation about the supposed dangers of vaccines.

Robert F. Kennedy Jr., an anti-vaccine leader, compared the issue to the Holocaust in comments in Sacramento before the screening of a scientifically unsubstantiated anti-vaccine film last week. An anti-vaccine group from Minnesota financed the airing of a television ad showing an infant having a seizure. Other vaccine opponents made similarly dubious claims about the risks of immunization in testimony to the Health Committee and jeered vaccine advocates from the audience.