David Armstrong writes in The New Yorker:
Opposition to vaccination is almost as old as vaccination itself. But Web sites like [Joseph] Mercola’s have helped drive the modern anti-vaccination movement. Most scientists consider vaccination one of the greatest public-health advances of the twentieth century, helping to control or even eradicate diseases such as smallpox, polio, and measles in the U.S. Studies have found that vaccines can have side effects, but they are almost always minor, like redness and swelling.
Anti-vaxxers blame vaccines for an increase in the rate of autism diagnoses among American children. From 2000 to 2014, the number of children diagnosed with autism-spectrum disorder increased to one in fifty-nine from one in a hundred and fifty. [David] Ayoub and others have argued that vaccines are one reason for this increase, though the U.S. Centers for Disease Control and Prevention has concluded that “studies have shown that there is no link between receiving vaccines and developing ASD,” and the World Health Organization has issued a similar finding. Prominent anti-vaxxers include celebrities such as the actress Jenny McCarthy and the lawyer Robert F. Kennedy, Jr. Before becoming President, Donald Trump weighed in, tweeting in 2014 that a “healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn’t feel good and changes – autism. Many such cases!”
A study published in September found that Russian trolls and sophisticated Twitter bots tried to foment confusion about vaccination and create a false equivalency between pro- and anti-vaccination arguments. The authors of the study, from George Washington University and other research institutions, warned, “Such strategies may undermine the public health: normalizing these debates may lead the public to question long-standing scientific consensus regarding vaccine efficacy.”
Please vaccinate your kids.