It turns out that measles isn't spread just by tourists at Disneyland. It's also incubated and disseminated through YouTube.
The authors -- Dr. Anand Venkatraman at the University of Alabama, Birmingham, Dr Nilay Kumar at Cambridge Health Alliance and Dr Neetika Garg at Beth Israel Deaconess Medical Center -- scoured YouTube, Google, Wikipedia and PubMed to see if there was any correlation between the ability to upload content and the prevalence of items linking vaccinations and autism. They found, not surprisingly, that there was.
"Support for a link between vaccines and autism is most prominent on YouTube, followed by Google search results" -- in other words, the two sites that give lay people the greatest freedom to post content for others to peruse, the authors wrote. Such support is far lower on Wikipedia, which allows readers to edit the content posted by others, and PubMed, a search engine that looks only at biomedical journals and works from academic publishers.
Vankatraman summed it up this way in an e-mail: "Websites which allow greater freedom of speech have a preponderance of views linking vaccines to autism." Those views weren't just celebrity pontifications, the authors found, but also scientific arguments offered by physicians and people with "official-sounding titles" designed to bolster their credibility.
Just to be clear here, Vankatraman and his colleagues don't adhere to the widely discredited view that early childhood vaccinations have been shown to cause autism. "Fears of vaccine-induced autism are the single most important component of the message that vaccine opponents propagate, although no scientific evidence for such a link exists," he wrote.
So, what to do about the "dominance of anti-vaccine voices" on open Internet platforms? The authors suggest that editors moderating content "can offer balance between free expression and factual accuracy," but that's a solution that doesn't work on YouTube's scale.
Although it's a cliched notion, I'm fond of saying that the solution to bad speech is more speech, not censorship. Here, that means having honest-to-goodness experts on vaccine science doing more to spread well-researched information online.
The problem is that the Internet enables -- and in some ways encourages -- people to cocoon themselves in information that supports their side of the debate. As much as Vankatraman might want to spread what science has shown about vaccines and autism, he can't inject his views onto an anti-vaxxer's Tumblr.
As long as parents want to believe that they shouldn't vaccinate their children, they will be able to find support for that point of view online. That's why two state senators have introduced a bill to require every California child to be vaccinated, with no exceptions for personal beliefs (just for medical reasons). It's a drastic step that reflects the stubbornly high rates of unvaccinated kids in many (typically wealthier) California communities.
Like virtually every form of medication, vaccines do have potential side effects. They're just not the ones that seem to get the most attention from the anti-vaxxers. And as the latest measles outbreak demonstrates, going unvaccinated poses risks too -- not just to yourself but to the people around you, particularly those too young or infirm to be vaccinated.
You might think that the public would have bought into the idea of universal vaccination by now. But as Venkatraman and his colleagues observe, the same technology that's speeding the flow of reliable information around the world is providing a megaphone to those who don't believe it.