Yes, that's a deliberately provocative headline. I chose it because that's what the media would like you to think your choices are. You can vaccinate your kids and risk giving them autism, or protect them against a number of dangerous, miserable, and potentially crippling communicable diseases. Does that protection cause autism? Is that really the choice? Or is it a false hypothesis hyped by the media and unsupported by real research? Is the Measles, Mumps and Rubella (MMR) vaccine a commercial conspiracy by pharmaceutical companies to make money, or are vaccines an actual health benefit?
We tend to have a love/hate relationship with science, often forgetting the many great things we owe it, like longer life spans, safe food, sanitation, miracle drugs, and technological wonders like the device on which you're reading this. As Louis CK pointed out in a video that's making the rounds, we're happy to bitch about our airline delays as though it were a day spent in Auschwitz while forgetting the mind boggling fact that we can fly. We're quick to point out the fact that thalidomide causes horrible birth defects and to ignore its effectiveness as a treatment for myeloma and skin lesions associated with leprosy. And in this case, we're eager to see a conspiracy of greed behind the rise in autism, instead of remembering that the lives of thousands, if not millions, of children have been saved and improved by vaccines. Even though a special US court has ruled that there is no evidence linking vaccines and autism, that disinformation is still being spread around, maligning a public health initiative that's really vital.
Let me throw just a few statistics at you, just to illustrate how important vaccines have been in the increasing quality of public health in the US alone.
- The incidence of polio dropped to nearly zero by 1960 (polio vaccine introduced in 1955)
- Measles cases dropped sharply between 1955 and 1970 (measles vaccine introduced in 1963)
- The incidence of congenital rubella syndrome dropped from an estimated 20,000 in 1964 to 7 in 1983 (the rubella vaccine was introduced in 1967)
Many of these diseases were already beginning to disappear when their vaccines were introduced, due to better sanitation, better nutrition, less squalid living conditions, germ theory, and better treatments, but diseases like polio, diphtheria, whooping cough, smallpox, and TB became virtually non-existent in developed nations (and in the case of smallpox, were completely eradicated except for a few frozen samples) thanks to public health programs of mandatory vaccination, and in the case of TB, mandatory treatment. As a result, I missed out on all those childhood diseases like measles, mumps, rubella, scarlet fever (which my mother had, and which left her with some heart damage), and whooping cough. I did get chicken pox because I'd already had it by the time the vaccine for it arrived in 1974. Born in 1960, I still remember the dread my mother expressed about the possibility of being struck by polio, or TB, and her stories of her siblings' sicknesses. We're so accustomed now to our children not having to suffer those diseases that we forget how frightening they were, and how devastating the consequences could be. We think of it as just one of those things you get as a child, but measles kills a quarter of a million people each year in undeveloped countries.
In developed countries, thanks to the prevalence of vaccinations, there's a pretty solid herd immunity, in which unvaccinated individuals are protected from catching diseases by the immunity of those who have been vaccinated. But there's a tipping point for herd immunity to, when the number of unvaccinated people begins to outstrip those vaccinated. This can occur on a small scale in communities, as it has with a measles outbreak on Long Island in 2008, which was part of a larger national epidemic, the largest since 1997. In this case, the carriers implicated were unvaccinated travelers. But there were unvaccinated individuals they brought it home to, as well. When that happens, a disease becomes endemic and a reservoir of infection is maintained that can spread once again when conditions are right, because no vaccine is perfect. Ideally, measles should not be endemic in the US, since we have effective vaccines for it. But not if there are people who don't get vaccinated because they think the risks from the vaccines are higher than the risks from the disease.
In 2005, a 17-year old unvaccinated girl visited Romania, caught measles, returned to her home in Indiana, and proceeded to infect at least 34 more people, most of whom were also unvaccinated.
I wonder how many of those people she infected were on the plane with her? I wonder how many of them took that infection home with them to their communities? We saw this kind of worldwide infection pattern happen with the SARS epidemic, which began in China in November 2002. "Eight months later, the international spread of Sars-CoV had resulted in 8,098 cases and 774 deaths in 26 countries."
Controversies of this sort have happened before, with predictable consequences. For instance, "[i]n the early 1970s uptake of diphtheria, pertussis, and tetanus vaccine in the UK was 81% and the incidence of pertussis was low. After a report in 1974 ascribing neurological reactions to the pertussis vaccine the public lost confidence in the vaccine and uptake fell to 31%: pertussis epidemics followed." In Africa, when a polio vaccination programme was derailed by suspicion of HIV infection in the vaccines, cases of polio soon skyrocketed from a few dozen to more than 800, many of them in countries where it had not been seen in years.
Phil Plait, over at one of our favorite blogs, Bad Astronomy, has been highlighting this issue for a while now, citing British doctor Ben Goldacre's media crusade against vaccine misinformation. Goldacre recently made an excellent video about the issue in response to what he sees as inflammatory and dangerous misinformation on a London radio station. One of the comments (by James Pannozzi*) on this particular post is really telling, as it expresses disgust with the the media for not giving equal time to "both sides of the story." What many people don't seem to understand, and what Goldacre highlights, is that the so-called controversy is now a manufactured one. There is no reasonable "other" side; there is only unsupported conjecture and outright falsehood. The facts of research show clearly that MMR is not implicated in autism. Any other opinion is just that: opinion, not fact. Science is all about debate, until the debate is resolved. Then the so-called debate becomes willful ignorance vs. proven fact.
One of the most telling statistics, for me, is the number of cases the original assertion about MMR was based on. It's actually worth quoting Goldacre's award winning article on the subject:
Wakefield [source of the original allegations] and his team found some traces of measles virus in the gut of 12 children with autism. That's the measles virus, not MMR. This lab finding has proved extremely hard for other labs to replicate. Professor John O'Leary of Coombe Women's Hospital in Ireland, a collaborator of Wakefield's, seems to have replicated the finding, and might have shown that the virus was from the vaccine, but it turns out maybe not. It's a very complex technical dispute, because it's hard to do the laboratory studies to prove if the traces are from a vaccine or infection, and it's not known what effect measles virus in the gut would have anyway. Either way, these are inconclusive laboratory findings on their own. And that, along with a number of understandably distressed parents, is the sum total of the case against MMR. It proves nothing about causation. It's all circumstantial: I'm sure you could find 12 children who hate Harry Potter, or have a missing toe, and have measles virus in their gut. That would prove nothing about MMR and hating Harry Potter, or missing toes. And children were starting to talk, or not, at about 18 months, for millennia before MMR was even dreamt of.
Twelve children. This entire controversy was based on findings from twelve children. In the world of statistics and medical studies, twelve is not enough to to even represent a true anomaly in the hundreds of thousands of cases of autism diagnosed each year. It's such a small fraction of 1% as to be insignificant, except to the families of those suffering with those diagnoses. Understandably, for them this is non-trivial because it represents some sort of explanation, no matter how tenuous. And humans always want an explanation for our suffering.
But refuting this number was a study in Finland that looked at "3 million MMR vaccinations, found only 31 cases of related gut symptoms, and not one of these children went on to develop autism in the next 10 years." So that incidence of virus traces in the gut actually means nothing other than that traces of the virus appeared in the guts 31 children out of 3 million who had received the vaccine, some of whom had autism, many more of whom didn't. Again, the occurrence of the virus in the gut is a tiny fraction of 1%, and the incidence of autism in those cases is . . . zero. Only a tiny fraction of children who received MMR showed traces of the virus in their guts, Wakefield's ostensible causation factor, and none of those went on to develop autism in 10 years. Correlation is not causation, and it's never been clearer than in this case. So as Goldacre puts it, "In the meantime, do you want the small risk of a small risk, or the definite risk of measles, which kills, blinds, and causes brain damage?"
Goldacre's evisceration of the bad science behind this manufactured controversy is really well done. Take a quick look, and then go read his award-winning article. And then go get your kids vaccinated, for all our sakes.
*Incidentally, the claim that Panozzi makes about Goldacre winning an award sponsored by GlaxoSmithKlein for his journalism on MMR is false partially true. The award Goldacre won was from the Association of British Science Writers, sponsored in later years by Syngenta, an agribusiness firm which has no connection to vaccines of any type. The 2003 award was sponsored in part by GSK, but none of the judges for the award were associated with GSK and GSK had no input on the final selection. Sponsors have changed many times over the years.