The largest study yet of connections between vaccines and autism has found that there is none.
Scientists are sometimes accused of producing results we already know. The problem however, can be in defining “we”. The evidence that vaccinating children does not cause autism is overwhelming, but plenty of individuals and organizations don't want to hear it. The fact that the latest work is published in the journal Vaccine will no doubt be all they need to dismiss this research as well.
The work in this case was a meta-study, combining the results of five previous studies involving 1,256,407 children with five case-controlled studies of a further 9920 children. Case controlled studies compare patients who have had a particular outcome, in this case a diagnosis of autism, with closely matched groups who have not to see if there was any difference in exposure to factors such as vaccines. The larger studies, on the other hand, looked at selections of the population to see what proportion of those who had been vaccinated developed autism, as against those who had not.
The findings were summarized as:
• There was no relationship between vaccination and autism
• There was no relationship between vaccination and Autism Spectrum Disorder
•There was no relationship between autism and the MMR vaccine
Just to rub it in, no relationship was found between autism and exposure to mercury, including in thimerosal, the mercury compound once used as a preservative for vaccines and products such as tattoo inks, but now discontinued for vaccines in the United States and Europe as a result of unproven fears.