A measles poster at Venice Family Clinic in Los Angeles, Calif. Feb. 5, 2015. Lawmakers in several US states are backing proposals to make it harder for parents to opt out of school vaccinations based on personal beliefs.
Photo by Lucy Nicholson/Reuters

Silicon Valley’s low vaccination rates threaten herd immunity


Some Silicon Valley daycares have dangerously low vaccination rates that threaten herd immunity, according to a Wired magazine report citing state data.

Herd immunity occurs when the vast majority of a population is immunized against a disease — it keeps the contagion out of communities, protecting those who are too young to be inoculated or those with auto-immune conditions that prohibit vaccination, for instance.

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For herd immunity to be effective, though, it requires a 92% vaccination rate, a level that wasn’t met at half of the California daycares affiliated with tech giants and analyzed by Wired magazine. The facilities reported to have low vaccination rates were affiliated with Google, Pixar, Cisco, and IBM.

Several companies said the data was old or incomplete. Another said no unvaccinated children attended their centers, despite the state data. It’s unclear why disparities exist in the numbers, but the data indicate that even in some of the brightest pockets of the country, anti-vaccination sentiments persist.

California’s low vaccination rates — particularly in wealthy neighborhoods of Los Angeles — have fueled a dangerous outbreak of measles, a disease that was nearly eliminated from the country 15 years ago, but has roared back to life partially because California law allows parents to exempt their children from vaccinations due to personal beliefs. 

The anti-vaccination movement has grown in recent years, as parents falsely believe that vaccines cause autism or other problems, despite science overwhelmingly showing vaccines to be safe. 

California and Vaccinations

Silicon Valley's low vaccination rates threaten herd immunity