The authors: Newsweek
Despite many scientific findings confirming the lack of a link between autism and vaccines given to children, community organizations that unite opponents of vaccination still hope to find evidence that vaccines threaten the health of children. Not so long ago, SafeMinds, an autism protection organization for patients with autism, funded research that was supposed to confirm that vaccines cause autism in children.
Between 2003 and 2014, SafeMinds and a number of organizations that unite opponents of vaccination provided scientists from the Southwestern School of Medicine at the University of Texas, the University of Washington, the Center for Children’s Health and Development. Johnson and other research institutions have about $ 250,000 to conduct a long-term study that evaluates behavioral and brain changes in rhesus monkeys, which were given a standard course of childhood vaccines.
The results of this study were published in the official journal of the National Academy of Sciences of the USA (PNAS). Scientists have concluded that vaccinations did not cause any changes in the brain and behavior of primates. This paper also reports on the results of a full-scale study from 2008 to 2014 at the National Primate Research Center in Washington, which began after the completion of the initial experimental program on 17 rhesus monkeys.
At this stage, 79 young macaques (aged 12 to 18 months) participated in the experiment, which were divided into six groups. Two groups received thimerosal vaccines according to the child’s routine vaccination schedule; two received a vaccine against measles, mumps and rubella (MMR) without thimerosal, and another two groups received just injections with saline as controls. In each case, the monkeys were further divided into subgroups: half were on the accelerated vaccination schedule recommended by the US Centers for Disease Control and Prevention in the 1990s, and half were vaccinated according to the schedule recommended since 2008.
Anti-vaccination agents claim that both vaccines with thimerosal, a mercury-based preservative, and MMR (CCP) vaccines cause autism. As you know, thimerosal was excluded from most vaccines in the late 1990s. But the researchers wanted to study its potential health effects anyway.
After the introduction of vaccines, monkeys were placed in separate cells to see if they showed any autistically similar features in their behavior, such as various fears, fear of relatives, desire for solitude, compulsive repetition of movements (for example, swaying), stereotypy (repetitive behavior). Scientists were convinced that the behavior of monkeys after the introduction of vaccines has not changed.
To confirm their findings, biologists also examined the brains of primates after euthanasia of animals. The team of scientists were interested in brain abnormalities, including the volume and density of the cerebellum, amygdala and hippocampus, which have some peculiarities in children with autism. Researchers also looked at the number and size of a certain type of brain cells — Purkinje cells — because some scientists found that there are fewer Purkinje cells in the brain of children with autism. However, there were no noticeable differences in the brains of monkeys from the vaccinated groups compared to primates from the control group.
It is clear that SafeMinds, which funded the study, is dissatisfied with the results obtained by scientists. Representatives of the nonprofit organization said that the results contradicted both the previous pilot study and the interim progress reports from the researchers.
SafeMinds head Lin Redwood, a registered nurse, said that in 2013 she received an email from researchers who reported a “statistically significant” 11 percent reduction in some types of hippocampal cells in vaccine groups, but the authors did not include these findings in the final article. In turn, Dr. Laura Hewiton, director of research at the Johnson Children’s Health and Development Center, an associate professor of psychiatry at the University of Texas Southwestern Medical Center, the lead researcher of the project, explains that at the time SafeMinds e-mailed it was clear to scientists that these data should be considered preliminary until all animals have completed the study. Moreover, she focused on the fact that none of the research procedures did not change after her team moved from a pilot program to a larger experiment.
“Similar results were obtained on a much larger number of primates by a team of biologists with ten years of experience working with primates. For example, in an experimental study, we studied 13 different innate reflexes from birth to 14 days in two groups of animals. In the current study, we examined the same 13 reflexes, plus six others from birth to 21 days in six groups of animals, that is, on a much larger scale, ”said Dr. Hewiton.
She explained that all the researchers involved in the data collection and analysis did not know which of the monkeys was in the vaccinated group and which was in the control group. Then her team invited an independent statistical consultant to analyze all the data, and also attracted two additional external researchers from different academic institutions. The conclusions of all three coincided.
“As you can see, we have done everything possible to ensure the accuracy and completeness of the data. My co-authors and I agree with the published conclusions. Also, the comprehensive nature of the current study shows why the results of an experimental study should be interpreted carefully, especially if a small number of animals are involved, ”concludes Dr. Hewiton.
But Sally Bernard, president of SafeMinds, would still like to re-analyze all the data: “We believe that in these data sets there are animals that can potentially negatively react to this vaccination schedule. Yes, the majority of vaccine recipients tolerate them well, but we believe that there is a subset that gives an adverse reaction. Considering the raw data, not the data as a whole, we can identify the subgroup in which this reaction took place. ”
Thus, this study refuted the hypothesis of the existence of any link between MMR vaccination (MMR) and autism, as well as between thimerosal in vaccines and autism. It has been suggested that there is some connection between the development of autism and the timing of vaccination, but this, too, was refuted. The goal of research is always some assumptions, it stimulates action. And I want to believe that scientific resources will be redirected to the study of new hypotheses.