The piece pointed to a 2008 San Diego incident where an unvaccinated 7-year-old boy caught measles in Switzerland and then passed the virus on to 11 other unvaccinated kids.
The Slate article comes as public health departments across the country are reminding parents to bring proof of vaccinations when enrolling their children in school.
In California, kindergartners need five DTaP (diphtheria, tetanus, pertussis), four polio, three hepatitis B, two MMR (measles, mumps, rubella) and one varicella (chickenpox) shot.
However, California is one of 18 states where parents may still enroll students who have not been immunized if they claim an exemption due to personal beliefs.
Out of the 334 children who enrolled as kindergarteners in Martinez last year, 4 percent started school without having received the battery of vaccinations required by the state because of the personal beliefs of their parents or guardians. That figure is higher than the statewide average of 2.7 percent and the Contra Costa County average of 2.1 percent.
With three unvaccinated students out of 59 arriving at kindergarten last year, John Muir had a personal belief exemption rate of 5 percent, the highest in the city.