The recent measles outbreak that has infected over 100 people from 14 states has sparked a national discussion about why some parents are still refusing to vaccinate their children in spite of a wealth of evidence confirming that vaccination is both safe and effective. It’s also made many Americans more aware of the risks the anti-vaccination movement poses to public health.
The anti-vaxxer hysteria can be traced back to one seminal event: the press conference called by London’s Royal Free Hospital in February 1998 to publicize a research paper, since retracted, that Andrew Wakefield had written for esteemed medical journal The Lancet.
During that conference, Wakefield presented his explosive findings — since found to be baseless — which he claimed connected the measles-mumps-rubella (MMR) vaccine to the onset of autism, a neurodevelopmental disorder characterised by impaired social interaction. Jeremy Laurance, a journalist who was there at the time, later called it “one of the biggest public relations disasters in medicine.”
The real disaster, it turned out, wasn’t just public relations but public health.
In the aftermath of Wakefield’s bombshell, professionals quickly discredited his conclusions. His far-fetched theory, Susan Dominus explained in a 2011 profile in The New York Times, was that “the three vaccines, given together, can alter a child’s immune system, allowing the measles virus in the vaccine to infiltrate the intestines; certain proteins, escaping from the intestines, could then reach and harm neurons in the brain.”
Wakefield based that idea on a case report involving only 12 children, a staggeringly low number of research subjects to investigate an intervention (vaccines) given to millions of children around the world.
There were plenty of reasons that experts were immediately sceptical. Case reports, Julia Belluz explains at Vox, are “basically just stories” and are among the weakest kinds of medical studies: They are observational and involve only a small sample of highly individualized cases that do not accurately represent the entire population. There are no controls. In Wakefield’s study, it was even worse: the cases were not randomly selected but carefully assembled — not the kind of data that can lead to conclusions, or even theories, about cause and effect.
Large-scale investigations involving thousands of participants in several countries (such as this Danish study of nearly half a million children) tried to recreate Wakefield’s findings, but none found any association between autism and the MMR vaccine.
Wakefield himself repeatedly declined to try to replicate his own findings, a process that is normally standard procedure to verify that the results of a single study, especially such a small and uncontrolled one, are not a fluke.
In 2010, after a thorough investigation that revealed not only bad science but also financial conflicts of interest, the original Lancet paper was retracted by the journal. “Part of the costs of Dr. Wakefield’s research were paid by lawyers for parents seeking to sue vaccine makers for damages,” Gardiner Harris wrote in the New York Times, in an article explaining the retraction. “Dr. Wakefield was also found to have patented in 1997 a measles vaccine that would succeed if the combined vaccine were withdrawn or discredited.”
“The data clearly appeared to be distorted,” one source, the father of a boy in the study, told Deer.
But by that time, the damage was already well underway. MMR vaccination rates across Britain, Ireland, the US, and other countries declined as parents learned of Wakefield’s theory, according to the New England Journal of Medicine. And a 2002 UK survey found that “nearly 50% of doctors reported parents were less willing to allow medical professionals to give vaccinations to their children,” the Washington Post noted.
More than a decade after his fateful press conference, after a long series of studies had failed to lend any credence to Wakefield’s speculation, he was asked by the New York Times whether he still believed that autism was caused by the MMR vaccine. “Is that a serious question?” he replied. “Yes, I do still think MMR was causing it.”
Indeed, many anti-vaxxers continue to unequivocally support Wakefield and his findings. They reject the studies that have again and again found absolutely no link between autism and vaccines, and consider Wakefield a hero — and a martyr. “To our community, Andrew Wakefield is Nelson Mandela and Jesus Christ rolled up into one,” J. B. Handley, co-founder of an anti-vaccine group, told The New York Times. “He’s a symbol of how all of us feel.”
California officials have been able to determine that, of the people infected with measles between late December and January 21, the vast majority (of those whose vaccination status was known) had never received the MMR vaccine.
The anti-vaccination movement that, according to The Los Angeles Times, won’t “get over its ignorant and self-absorbed rejection of science,” has been credited with driving the measles rate to a 20-year record high in 2014. The 102 cases so far this year suggest that 2015 could be on track to be even worse.