In medicine the benefits of childhood vaccination are widely accepted. The evidence is clear and overwhelming: vaccines do not cause autism (or any other condition), and the benefits of preventing severe diseases far outweigh the small risks of side effects. This is non-controversial, and vaccination is a staple of preventive medicine worldwide.
In political circles, however, the topic has become an issue in the presidential race. Republican nominee Donald Trump has changed his position on vaccines, suggesting at different times that they are both dangerous and safe. In March 2014 he tweeted "Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn't feel good and changes - AUTISM. Many such cases!"
But a year later during a Republican debate said "I am totally in favor of vaccines, but I want smaller doses over a longer period of time."
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The following day the American Academy of Pediatrics issued a statement to "correct false statements made during the Republican presidential debate last night regarding vaccines. Claims that vaccines are linked to autism, or are unsafe when administered according to the recommended schedule, have been disproven by a robust body of medical literature. It is dangerous to public health to suggest otherwise...Vaccines work, plain and simple. Vaccines are one of the safest, most effective and most important medical innovations of our time."
Green Party candidate Jill Stein, who is a medical doctor, posted a July 31 tweet that "There's no evidence that autism is caused by vaccines," but within five minutes deleted that statement and replaced it with a somewhat more equivocal position: "I'm not aware of evidence linking autism with vaccines."
This subtle change did not go unnoticed; a writer for "Slate" expressed concern that "the Harvard-trained physician is catering to vaccine skeptics by engaging in a bit of double-speak. Stein acknowledges that vaccines have done enormous good for public health and says she supports them. But she simultaneously suggests that there may be unresolved 'questions' about their safety and makes broad claims that the American drug-approval process has been tainted by corporate influence.... Stein's latest vacillations on Twitter haven't helped the impression that she's trying to avoid alienating anti-vaxxers without outright bear-hugging them."
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