The Institute of Medicine, an independent organization under National Academy of Sciences designed to provide advice on issues of health, recently published yet another report on vaccine safety a few days ago. Earlier reports, focusing on the supposed association between the measles-mumps-rubella vaccine and autism, thimerosal and autism, the hepatitis B vaccine and demyelinating disorders like multiple sclerosis. The reports reviewing the research on these issues found that the postulated associations where not supported by the evidence or that the evidence favors a rejection of a causal relationship.
This, of course, did not even put a dent in the conspiracy theories about large pharmaceutical companies and vaccines. The funny thing about conspiracy theories is as more and more evidence piles up against it, the proponents usually claim, in a puff of cognitive dissonance, that the researchers are part of the conspiracy, bought by the pharmaceutical companies. Never mind the fact that the reviewers where independent and has never been involved in vaccine safety or anything like that before. Soon, the supposed conspiracy grows to such an absurd size that it would not have been manageable without leaks.
This new report, entitled Adverse Effects of Vaccines: Evidence and Causality, is a result of a detailed review of the scientific literature spanning over 1000 articles and, while finding evidence of extremely rare adverse events like seizures and inflammation of the brain, they did not find any evidence for associations such as autism and type-I diabetes. The report brief concluded that:
Vaccines offer the promise of protection against a variety of infectious diseases. Despite much media attention and strong opinions from many quarters, vaccines remain one of the greatest tools in the public health arsenal. Certainly, some vaccines result in adverse effects that must be acknowledged. But the latest evidence shows that few adverse effects are caused by the vaccines reviewed in this report.
A Nature News article entitled Vaccines given a clean bill of health noted that
On 135 other possible links between the vaccines and adverse effects, the panel concluded that there was “inadequate evidence to accept or reject a casual relationship”.
In the natural sciences, this means that the evidence was inconclusive and that we have to suspend judgment on this issue until further evidence is gathered. This is either because there has been no research on it or that the research that has been done is flawed or limited, or both. I suspect, however, that the anti-vaccine crowed will interpret this as supposed associations that “cannot be refuted” and that, like creationists postulate a divine designer in the gaps of science, they will continue to assert that there is a causal relationship, or that the government (despite the fact that Institute of Medicine is an independent organization) is somehow hiding the evidence.
For those that already accept the position that vaccines are safe in general (although vaccines, just like any other product, must be evaluated at a case-by-case basis), this is hardly news, but for those that reject vaccines, this will probably just reinforce their beliefs that the population is being brainwashed by the government and large pharmaceutical companies and that they, as martyrs, are being oppressed by the establishment. A classical example of pseudoskeptic debating tactics.