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Thursday, November 23, 2017

Vaccine Update

 In The Politics of Autism, I look at the discredited notion that vaccines cause autism.
The Food and Drug Administration credits vaccines for the decline of many infectious diseases over the last century, and more than a decade of peer-reviewed studies show there is no link between their use and autism.
However, a story perpetuating the myth that vaccines cause autism has prompted several questions to and has been getting popular on Facebook, where it was flagged by the social network’s users as potentially false. It is.
The headline on the story says: “NOW IT’S OFFICIAL: FDA Announced That Vaccines Are Causing Autism!”
But the FDA has made no such announcement, and the only evidence that the story gives to support its claim is the label from a vaccine called Tripedia, which was discontinued in 2011.
That evidence is pretty weak, since the label for Tripedia lists autism along with 10 other “adverse events” that were voluntarily reported by doctors or parents who had their children get the shot. Autism was not found to be among the effects identified in the studies of that drug before it went to market.
Julia Belluz at Vox:

While vaccine refusal rates have overall increased since 2011, they leveled off 2013 through 2016, researchers writing in the journal Open Forum Infectious Diseases found.
During the study period, there were important legislative advances in vaccine policy, which went into effect after the study ended. In July of 2016, Vermont banished its philosophical exemptions, and California also did away with all nonmedical exemptions. [But note that some parents are getting dubious medicale exemptions. -- JJP]
Legislation in other states generally seems to be heading in a more pro-vaccine direction. One JAMA paper looked at the 36 vaccine bills considered between 2009 and 2012: 31 wanted to expand them, making it easier to opt out of vaccines, while only five wanted to make vaccine exemptions more difficult to obtain.
None of the 31 anti-vaccine bills passed, while three of the five bills clamping down on vaccine deniers made it through. So while there was more activity from the anti-vaccine side, public health has been winning out in state legislatures.
But there are refusal hotspots.
In Texas for example, between 2003 and 2016, there’s been a 19-fold increase in vaccine refusals — and it hasn’t leveled of lately. “We are still seeing an aggressive increase in nonmedical exemptions [here in Texas],” said Peter Hotez, a pediatrician at Baylor College of Medicine, “with at least 52,000 last year, up from 45,000 the year before.”
Texas is one of those lax states that allows parents to get both religious and philosophical vaccine exemptions (unlike Mississippi, West Virginia, and California). Researchers have continually found these more permissive places have higher rates of vaccine refusals — a trend that appeared again in the Open Forum Infectious Diseases paper. In the study, the rate of exemptions was 2.41 times higher in states allowing both religious and philosophical exemptions compared to those that allowed religious exemptions only.
Taking the much longer view, since the early 1990s, vaccine exemptions have overall been trending upward. In one 2009 New England Journal of Medicine paper, researchers looked at the state-level rates of non-medical exemptions and found that, between 1991 and 2004, those rates increased from less than 0.98 percent to about 1.5 percent. According to the new study, we’re now hovering above the 2 percent exemption rate, which translates to thousands more unvaccinated children than just a decade ago.