The Bay Citizen has reported extensively on the whooping cough epidemic in the Bay Area. With a new school year starting, some local health departments are concerned that unvaccinated children could contribute to the disease's spread. Under state law, parents can sign "personal belief exemption" waivers, declining to immunize their children from whooping cough or other diseases.

Up-to-date immunization rate in Bay Area counties 91.75%
In public schools 92.22%
In private schools 88.91%

s: http://www.baycitizen.org/local/counties/immunizations/