https://www.nytimes.com/2017/05/05/u...-vaccines.html

... the community was “targeted” by members of the anti-vaccination movement, adding that vaccination rates in the community had been as high or even higher than those in the white population, but that began to change in 2008.

Members of the community came to believe incorrectly that they had an unusually high rate of autism and that the cases were related to vaccines. But later studies showed that their autism rates were not out of line with those of the state’s white population, he said.
More in-depth article:

https://www.washingtonpost.com/natio...86f_story.html

I don't know what's more depressing, that this vulnerable population has fallen prey to the machinations of one of the most harmful movements in the West today, or that xenophobic and racist groups--about as likely to count anti-vaxxers among their ranks as any enclave of middle-class Californian moms might be--are using this as yet another way to attack refugees.