Two years after California tightened its school vaccination rules, more and more parents opposed to the shots are finding ways to avoid them.

The anti-vaxxers, as they’re known, are turning to doctors to gain exemption for their children, according to a report from the Los Angeles Times.

The result is that in some Bay Area kindergartens, the vaccination rate is less than 50 percent.

California Senate Bill 277 did away with what were called “personal belief exemptions.”

Parents could no longer simply say, “I don’t believe in vaccinations.”

Now, many of them are turning to their doctors, especially in the Bay Area.

In Sebastopol, Petaluma, Santa Rosa, Sausalito, and Berkeley, the percentage of kindergartners with medical exemptions for vaccines ranges up to 58 percent.

They are fueling a trend that has seen the number of medical exemptions statewide climb.

From under 1,000 in 2013, they have quadrupled to more than 4,000 last year.

Doctors say only about 3 percent of all children can’t tolerate vaccines–if they have a gelatin allergy, for example, or are in chemotherapy.

And if more than 10 percent are not immunized, they lose what is known as “herd protection.”

The CDC says when only a few people are immunized, diseases spread easily from one individual to another.

But if enough people are protected, the individual is isolated.

And in cases of highly contagious diseases like measles, as many as 95 percent of people need to be vaccinated.

The California Senate bill was passed after a measles epidemic was traced back to Disneyland.

Legislators are now talking about tightening the rules even more to limit how doctors can grant exemptions.

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