Our Vaccine Database Methodology

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By Olivia Allen-Price and Lisa Aliferis

Entering kindergarteners in California are required by state law to be vaccinated against a range of diseases. While the overwhelming majority of children are vaccinated, some parents opt-out of vaccines for their children. In California, this "personal belief exemption rate" (PBE) has doubled over seven years.

State of Health published a database where people can look up any school in the state to see the PBE rate for its kindergarteners.

We obtained data from the state from its kindergarten assessment of vaccination rates which is conducted each fall. The data shown in our post cover eight years, from the 2007-2008 school year through the 2014-2015 school year, the most recent year for which survey data are available. More than 500,000 children in 8,000 public, private and parochial kindergartens in California are included in the survey annually. The assessment is done at the school level and reported to local health departments and to the state.

The state then compiles a report of the immunization status of all kindergarteners, a table with dozens of columns of information. More than 90 percent of kindergarteners in the state start school fully immunized. But some children have “conditional” status, meaning they are lacking some vaccines, and schools are obligated to follow up with those children to ensure their vaccination. Officials told us they do not want to deny entrance to school because the child is not fully up-to-date, but is expected to be soon.


To make it easier for readers to look up the PBE rate at their own school, we simplified the state’s table. We did not alter the data in any individual column. Instead, we selected six of the columns that we thought readers would find most interesting. In addition, we made the data sortable by county, city, school district and PBE rate.