Vaccines scare people. They always have, and perhaps they always will. We are injecting a vial of something evil into us, after all — some dead or weakened strain of a harmful virus, which seems to go against good reason.
Today the fear is that vaccines cause autism. Despite numerous well-crafted studies in the past decade finding no such connection, this fear lingers. Soon, hopefully, we will understand autism's cause and develop treatments. But, judging by history, vaccine fears will likely remain.
In the early 1900s, the fear was that vaccines were causing a new epidemic called cancer. In the 1950s, Americans were convinced that smallpox and polio shots would give them these diseases. In the 1980s, many thought vaccines caused Sudden Infant Death Syndrome. Vaccines are a logical culprit.
A perfect storm
The vaccine-autism link is feasible, and research investigating this link is money well spent. But, according to a paper published in February in the American Journal of Public Health by Jeffrey Baker of the Duke University School of Medicine, the origin of the theorized link was based less on science and more on separate histories that happen to converge:
- Mercury identified as an environmental pollutant causing neurological disorders, in the 1960s;
- Autism defined as a spectrum of disorders, in the 1970s;
- Number of childhood vaccines increasing, in the 1980s;
- The Internet in the 1990s.
Baker traced the perceived rise in autism rates to the efforts in the late 1980s to count the number of children with the disorder. As the numbers climbed, it appeared that an epidemic was occurring — a theory still debated, for it is difficult to understand the rate in the era before autism was defined.
Educated parents of autistic children quickly grew frustrated with the lack of therapies and public services available, Baker said. They began to network and look for answers. Many parents latched on to alternative theories, most infamously that of Andrew Wakefield, who proposed that a "leaky gut" could release toxins that affect the brain. Wakefield's paper in Lancet in 1998 linking autistic regression and diarrhea following measles-mumps-rubella (MMR) shot fueled a nascent autism-vaccine movement. The study, however, has since been thoroughly refuted.
Does the M matter?
Meanwhile, environmentalists were growing alarmed by concentrations of methylmercury in the waterways and in fish, which can cause a range of neurological problems. Congress acted with a law that required the FDA to assess the levels of mercury in various products. Some vaccines contained ethylmercury as a preservative.
Ethylmercury is not the poison that methylmercury is. The difference is analogous to ethanol (in wine) and methanol (wood alcohol, the stuff that makes you blind before it kills you). Lacking a standard for ethylmercury, however, the FDA stated in 1999 that vaccination would introduce levels of ethylmercury that were higher than the safety limit for methylmercury.
Well, that didn't ease fears. The autism-controversy grew, even though the MMR vaccine didn't even contain ethylmercury. That's where the Internet kicked in, that repository of half-truths with countless websites promoting Wakefield's theory and exposing the dangers of mercury — connected only in the "vaccines, pharmaceuticals and pollution are bad" sense.
This seemed logical: Autism rates were climbing; the number of vaccines was growing; a real journal published a real paper claiming some kind of link; and the news media never explained the nuance of mercury compounds.
The next stage
The autism-vaccine movement is evolving into something new. Maybe it isn't the mercury, removed from most vaccines years ago. Maybe it isn't the leaky gut thing, either. Maybe it's the bombardment of all these vaccines on a young immune system.
This is another legitimate theory worth investigating, but it likely won't hold up. While the number of vaccines has grown, the vaccines themselves are more sophisticated with fewer antigens — substances that induce the immune response — so the body is actually getting less of a workout these days.
Wouldn't it be prudent to space out the vaccines, just in case? That's a public health nightmare. You would leave children vulnerable to deadly or disabling diseases for an extra year or likely more; vaccination schedules are hard to keep up as it is.
Okay, then can't I back out of the vaccine program on personal or religious grounds? That's what's happening in Nigeria with the polio vaccine. As a result, polio has spread from Nigeria to 23 other countries, many predominantly Muslim and as far as Yemen and Indonesia, paralyzing at least 1,500 children since 2003, according to the World Health Organization.
Nigerians have their fears, too: Vaccines can carry HIV and render children infertile. Whatever your fears are, the poliovirus is a plane-ride away.
Christopher Wanjek is the author of the books “Bad Medicine” and “Food At Work.” Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LiveScience.
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Christopher Wanjek is a Live Science contributor and a health and science writer. He is the author of three science books: Spacefarers (2020), Food at Work (2005) and Bad Medicine (2003). His "Food at Work" book and project, concerning workers' health, safety and productivity, was commissioned by the U.N.'s International Labor Organization. For Live Science, Christopher covers public health, nutrition and biology, and he has written extensively for The Washington Post and Sky & Telescope among others, as well as for the NASA Goddard Space Flight Center, where he was a senior writer. Christopher holds a Master of Health degree from Harvard School of Public Health and a degree in journalism from Temple University.