California strikes down exemptions to vaccination requirements for schoolchildren

California Gov. Jerry Brown

Despite virulent opposition, California Gov. Jerry Brown signed a bill this week making the state the largest requiring schoolchildren--public and private--to be vaccinated unless there is a medical reason not to do so.

The bill, SB 277, requires children to be vaccinated against diphtheria, tetanus and pertussis; measles, mumps and rubella; polio; hepatitis B; and chickenpox in order to attend schools and strikes down the state's exemptions for personal and religious reasons.

"The science is clear that vaccines dramatically protect children against a number of infectious and dangerous diseases," Brown said in a statement. "While it's true that no medical intervention is without risk, the evidence shows that immunization powerfully benefits and protects the community."

The bill's passage followed months of hostile debate in California and nationwide over philosophical and religious exemptions for vaccinations after a measles outbreak started in Disneyland and sickened more than 150 people across the U.S., Canada and Mexico. California joins Mississippi and West Virginia in having the toughest vaccines laws on the books.

In February, as the outbreak unfolded, measles-jab maker Merck ($MRK) said it could only do so much to encourage vaccinations, and that the task lies with the government and other advocacy groups.

Much of the controversy stemmed from a now-discredited study linking the MMR vaccine to autism, resulting in 800 Californian schools with vaccination rates below 92%, the threshold for herd immunity.

"We hope and expect we will be a model to get us back to where we should be, which is that cases of measles and other preventable diseases do not need to be something we live with," State Senator Richard Pan, a pediatrician and the bill's author, told The New York Times.

In their response, some opponents said the law threatens personal rights and that they will turn to homeschooling, while others speculated whether the law will spur other states to make similar efforts. Last year, 11 states took up the issue, but many were halted due to opposition.

- here's the governor's statement (PDF)
- get more from NYT and a take from Vox