The scientists whose research anti-vaxxers use to claim their children should be genetically exempt from vaccines have now said their old work is no longer valid.
Anti-vaxxer doctors and even parents have been ordering genetic tests from companies like 23andMe in search of a variant of the MTHFR gene in their patients and children.
That’s because a 2008 study suggested that people with that variant would be prone to ‘adverse events’ in response to smallpox shots (which are no longer given).
But two of its authors, Dr James Crowe and Dr David Reif now say that our understanding of and methodology for studying DNA have changed so drastically that their decade-old research is no longer valid, they told The Atlantic.
A decade-old study suggested a link between a gene variant and reactions to a smallpox vaccine – which is no longer used – which anti-vaxxers cite to justify medical exemptions. The study’s authors say the research is ‘no longer valid’ by today’s standards (file)
California’s law against philosophical exemptions to vaccines was passed in 2016 in the aftermath of a brutal measles outbreak that began at Disneyland.
But that didn’t stop vaccine wary and anti-vaccine parents – still concerned over now-debunked research linking the MMR vaccine to autism – from finding ways to get their children out of the shots.
In the last two years, the number of ‘medical’ exemptions from shots issued in California has tripled, according to a JAMA report.
And just because it’s labeled ‘medical’ and issued by a doctor, doesn’t necessarily mean they are medically valid.
For example, Dr Kenneth Stoller in San Francisco was subpoenaed earlier this month by the city attorney on suspicion that has been issuing improper vaccine exemptions and profiting from the practice.
According to city attorney Dennis Herrera has been using no more than ‘two 30-minute visits and a 23andMe genetic test’ to determine that children should be exempt from shots.
Online resources, too, instruct consumers on how to upload the raw data from their at-home DNA tests to look for a variant of a gene called MTHFR (which 23andMe’s genetic profiling will detect, but the company doesn’t specifically test for), that has been linked to ‘adverse effects’ from smallpox vaccinations.
But 23andMe itself says that its tests should not be used as the basis of medical decisions.
Smallpox vaccinations are not given any more, because the disease is considered eradicated.
And, now, the scientists who reported the MTHFR-vaccine reaction link say the genetic variant doesn’t do what they thought it did.
In 2008, Dr Reif, Dr Crowe and their colleagues published a study in the Journal of Infectious Disease linking MTHFR to ‘systemic adverse events,’ or reactions, to the smallpox vaccine.
Adverse effects were defined, for the study’s purposes, as fever, rash or swollen lymph nodes (an immune system response) in the area of the shot.
The researchers gave smallpox shots to over 130 healthy adults that had never had the vaccine, and watched them for any of these symptoms, then analyzed their genomes.
Those that had a certain variant of MTHFR were more likely to have these non-life-threatening reactions.
But, for one, the effects were from the smallpox vaccine, which hasn’t been routinely in the US since 1972, and wouldn’t necessarily occur with a different vaccination.
And, when the study resurfaced in a 2016 lawsuit, its authors decried their own methodology as outdated.
‘It’s just not even a valid study by today’s methodology,’ lead study author Dr James Crowe, who is now director of the Vanderbilt Vaccine Center, told The Atlantic.
‘It’s not even a valid study by today’s methodology.’
He added that applying the study’s findings to the MMR vaccine as a basis for medical exemption is ‘illogical and inappropriate.’
Beyond changing methodologies, we simply know a lot more about genes and the way genetics work than we did a decade ago – including that the MTHFR gene has broad ranging effects.
MTHFR codes for an enzyme key to the body’s ability to make proteins.
And some 40 percent of us have the variant that Dr Crowe and his team originally linked to ‘adverse reactions’ to the smallpox vaccine (which is not used and is not the same as any of the vaccines used today).
None if this research has made the same waves that Dr Crowe and Dr Reif’s 2008 study did, apparently.
That didn’t stop 23andMe customers from asking more about the MTHFR gene than any other.
23andMe, however, wrote a blog post trying to put consumers’ fears to rest.
‘Despite lots of research – and lots of buzz – the existing scientific data doesn’t support the vast majority of claims that common MTHFR variants impact human health,’ the company wrote on its blog.
But doctors who conspire with parents to get inappropriate medical exemptions from vaccines for their children are still blaming genetics.
So Dr Crowe and his co-authors are taking matters into their own hands, according to The Atlantic, but writing to the Journal of Infectious Diseases begging it to say that their research doesn’t say much at all.