Daniel Summers
AT WHAT point does a body of evidence become massive enough to count as proof ? When has a question been answered enough times that it can be put to rest?
When it comes to the safety and effectiveness of vaccines, it seems as though public health advocates must constantly roll the burden of proof toward a mountaintop that never comes into view.
The latest salvo against vaccinations came courtesy of Robert Kennedy jr and Robert de Niro. At a joint appearance this week, Kennedy offered $100 000 (R1.3 million) to anyone who could turn up a study showing that it is safe to administer vaccines to children and pregnant women, with a specific call out to concerns about mercury. De Niro was there to lend his endorsement and a patina of gravitas.
Both men have an unreliable history when it comes to their views about vaccinations. Kennedy’s reference to mercury alludes to thimerosal, a preservative once used in vaccines, which he has long maintained can lead to autism. (It doesn’t.) A meeting earlier this year between then President-elect Donald Trump (who has hair-raising views about vaccines) and Kennedy caused grave concern within the medical community. Kennedy claimed Trump asked him to helm a commission on vaccine safety (even though the US already has one), but it has yet to materialise.
De Niro came under fire for endorsing a film that purports a link between vaccinations and autism, although instead of mercury it blames the measles/mumps/rubella (MMR) vaccine. The Tribeca Film Festival, which he co-founded, included the anti-vaccine documentary in its 2016 line-up. After complaints, it was pulled, but the actor touted its message and urged people to see it. He hasn’t changed his mind.
I can think of many handy uses for a spare hundred grand, and would gladly sit down and share my experience as a paediatrician with De Niro and Kennedy. It’s nearing two decades since I graduated from medical school, and in that time I’ve immunised thousands of patients. Not once have I encountered a case where those immunisations could be plausibly linked with autism.
In the off chance that my word alone isn’t sufficient to collect the $100 000, I’m happy to proffer lots of studies that support the safety of vaccines. Studies never seem to settle the question for anti-vaccine activists, but they are the best evidence we could ever have, based on millions of people and using many different types of comparisons, that vaccination is safe for kids.
The explanation for the bogus vaccine-autism link is a constantly shifting target. As noted, the MMR vaccine and thimerosal have been blamed, and the anti-vaccine movement happily gloms on to both explanations despite the fact they are unrelated. That the various theories never cohere doesn’t seem to give the movement pause. Uncertainty is good for stoking fear. RESEARCH: Studies are the best evidence that vaccination is safe for kids.
When studies show that the MMR vaccine doesn’t cause autism, and when the original study suggesting a link is exposed as a fraud, it must be thimerosal. Other studies show no association between thimerosal and autism, and thimerosal isn’t used anymore? A combination of all the vaccines at once is the problem. Produce evidence to support the safety of the current vaccination schedule, and the bogeyman simply adopts another form.
Because much of the evidence in support of vaccines comes from the Centres for Disease Control and Prevention, detractors seize on corruption as an explanation for studies with findings contrary to their beliefs. The anti-vaccine movement affords the CDC as much respect as