Vaccines and Autism: Is the Debate Over?

Vaccines are turning out to be a topic of major contention in 2019. The World Health Organization began the year by declaring vaccine hesitancy one of the top health threats. Some U.S. states, including Washington, are seeking to make exemptions more difficult to obtain. Facebook is trying to minimize “anti-vax” groups, and Amazon appears to have banned anti-vaccine documentaries from its Prime Video service.

Much of the medical establishment insists that vaccines are safe and necessary to prevent outbreaks of contagious diseases, and with minimal side-effects. On the other hand, “anti-vaxxers” suggest that little safety testing has been done on inoculation formulas and that Big Pharma has a financial interest in pushing them onto a scared public. With measles outbreaks occurring with increased frequency across the U.S., some may be asking themselves, to vaccinate or not to vaccinate?

The debate surrounding vaccine safety has largely revolved around the idea they may cause or contribute to the development of autism in young children – particularly in the case of the Measles, Mumps, and Rubella (MMR) formula. One argument against vaccines is not based on the medical theory behind them, but rather the execution – some concoctions include added ingredients, such as aluminum and the mercury-containing preservative Thimerosal. While the MMR vaccine does not contain these suspected neurotoxins, it is still one of the most controversial in use today. The data has been hotly contested, but those in favor of vaccines now have a new piece of evidence in their favor. Danish scientists have just published a report after ten years of research that found no link between autism and the MMR vaccine.

No Link Found

The study recently appeared in the Annals of Internal Medicine, an influential journal published by the American College of Physicians. A team of Danish researchers sought to address ongoing public concern about a potential link between autism and the MMR vaccine, and tracked the statistical health data of 657,461 vaccinated and unvaccinated Danish children over a decade – no physical examinations of the subjects or their medical records occurred; rather, the information was drawn from population registry records. The study was particularly geared to investigate the risk to children thought to be more susceptible to autism. While 1% of the children studied did develop the condition, the scientists concluded that vaccinated children showed no increased incidence compared with the others, even in cases where a child was thought to have a higher risk. The report states:

The study strongly supports that MMR vaccination does not increase the risk for autism, does not trigger autism in susceptible children, and is not associated with clustering of autism cases after vaccination … We found no support for the hypothesis of increased risk for autism after MMR vaccination in a nationwide unselected population of Danish children; no support for the hypothesis of MMR vaccination triggering autism in susceptible subgroups characterized by environmental and familial risk factors; and no support for a clustering of autism cases in specific time periods after MMR vaccination.

While vaccines were not observed to contribute to the development of autism, the study did reveal a few important statistics about what other factors may be involved – the greatest risk factor was sex, with boys being most likely to be diagnosed as autistic. Children born during the later stages of the study (2008-2010) were at higher risk of autism than those born earlier, suggesting that the condition is becoming more prevalent over time, and very rapidly so. Children with autistic siblings were also at greater risk of developing it themselves.

A Medical Mystery

With this study adding to a series of similar findings, why does the debate about autism and vaccines continue? The scientists say in an article written to accompany the study that no amount of data supporting the safety of the MMR vaccine will convince skeptics that it does not lead to autism. Their proposed solutions being for the medical community are to find alternate explanations for autism and, essentially, to suppress and confront “misperceptions regarding vaccines and autism.” They write:

“First, any myth should be clearly labeled as such. For example, there is evidence that a misleading headline can induce a reader to remember the inaccurate information while discounting the correct information presented subsequently. Second, while confronting the erroneous information, the focus should be on a few key facts; it is not essential to rebut every piece of misinformation.”

The scientists blame a 1998 article by Dr. Andrew Wakefield for the ongoing rumors that vaccines and autism are linked, which have continued to be expressed via social media. In a review published in the medical journal The Lancet, Wakefield was the first to propose the connection. The article was later discredited and Wakefield was accused of several indiscretions, including unethical conduct and fraudulently manipulating the data for financial gain. His medical license was revoked and the article retracted by the journal. Wakefield – who trained and worked as a gastroenterologist – continues to allege the MMR vaccine can indirectly contribute to autism by causing bowel inflammation, which in turn can have neurological effects. According to Wakefield, many of the autistic children he studied were suffering from chronic bowel disease. He also denies being against vaccines as a whole. In a 2010 interview in which he describes his own account of his fall from grace in the medical field, he argues in favor of vaccines if they are thoroughly researched for safety, and blames unsafe practices for loss of faith in the procedure that has led to the “anti-vax” movement and a resurgence in contagious diseases such as measles.

Interestingly, when vaccines are taken out of the equation, medical science is prepared to accept the idea that bowel health may be related to autism. Research into the “microbiome,” a.k.a. digestive bacteria in the intestines, has been increasingly in the medical spotlight of late and some research indicates it can have wide-ranging psychological and neurological implications. A July 2018 study at the University of Virginia suggested that a pregnant woman’s gut health can impact that of her children, and that changing an expectant mother’s diet or administering probiotic supplements may be used as a preventative measure against her child becoming autistic.

Autism continues to baffle scientists, although young people are experiencing it at increasing rates that are projected to get even higher, especially among boys. Will the Danish report help to end the debate over the MMR vaccine – or are these scientists right in their claim that nothing will help, until another explanation can be found to shed light on this mysterious condition?