Some of the people who are determined to believe that there is a link between childhood vaccinations and autism have rejected all the scientific findings so far that have shown no link, suggesting that there is a collusion between scientists and the pharmaceutical industry to hide the truth. In order to bolster their case, some of them who belong to a group known as SafeMinds commissioned a study to find just such a link. The researchers have come back with their conclusion that they could not find any such connection.
Between 2003 and 2013, SafeMinds provided scientists from the University of Texas Southwestern School of Medicine, the University of Washington, the Johnson Center for Child Health & Development and other research institutions with approximately $250,000 to conduct a long-term investigation evaluating behavioral and brain changes of baby rhesus macaques that were administered a standard course of childhood vaccines. (The National Autism Association, another organization that has questioned vaccine safety, also provided financial support for this research.) The latest paper in the multiyear project was published Monday in the Proceedings of the National Academy of Sciences (PNAS). In it, the researchers concluded that vaccines did not cause any brain or behavioral changes in the primates.
So did the people at SafeMinds change their minds? Don’t be silly.
SafeMinds, the nonprofit that funded the research, is not happy with the results. Representatives from the group say the findings contradict both an earlier pilot study and interim progress reports the organization received from the researchers.
SafeMinds also believes that the research team behind the new PNAS study may have cherry-picked their data. SafeMinds Director Lyn Redwood, a registered nurse, says she received an email in 2013 from the researchers reporting a “statistically significant” 11 percent reduction in certain types of hippocampal cells in the vaccine groups. But she says the authors did not include these findings in the new paper.
But there is a reason for that.
Dr. Laura Hewitson, director of research for the Johnson Center for Child Health & Development, an adjunct associate professor in the Department of Psychiatry at the University of Texas Southwestern Medical Center, a lead researcher on project and co-author on all four papers, says that at the time that email was sent, it was also made clear to SafeMinds “that the data should be treated as preliminary until all of the animals had completed the study.” She added that none of the study’s procedures changed once her team moved from the pilot program to a larger sample.
It is not at all unusual for pilot studies to not stand up to a full study because of the larger statistical fluctuations of small sample sizes.
[Alycia Halladay, chief science officer at the Autism Science Foundation] likens the challenge of disputing the claim that vaccines cause autism to “playing whack-a-mole.”
“First, the proposed association was between the MMR vaccines and autism,” she says. “Then that was disproven. Then it was the thimerosal components in vaccines; now that has been further disproven in a carefully designed animal model study that aimed to specifically examine that question. It has also been suggested that the association is because of vaccine timing, but that too has been disproven. The target always seems to be moving, and the expectation is that scientific resources will be diverted to address each new modification of this hypothesized link.”
There is no convincing some people once their minds are made up.