Statistics are showing that autism rates have raised a lot in developing countries in the past 20-30 years. According to the United States CDC, about 1 child out of every 150 was diagnosed with an ASD (autism spectrum disorder) in 1992. The number of children who received an ASD diagnosis was about 1 in 68 for children born in 2004. The problem is that we can’t accurately compare these new autism rates to the ones from the 1940s to the 1980s.
In this period, the ASD was associated primarily with individuals who were severely affected. This is probably a reason why the rate of the condition was only about 1 in 10,000. Our understanding of autism has expanded greatly in the 1990s, and this is the reason why individuals who weren’t associated with the condition before might be classified with ASD now. Also, this is the reason why a lot of people ask themselves “Do vaccines cause autism?”
Vaccines concerning ASD
The doctors are still not sure why we have such high rates of ASD nowadays. It could be because more people are aware of the disorder so there’s an increase in reporting and diagnosis. But, it could also be the autism definition changes or an actual ASD development increase due to a third factor (usually thinking that vaccines cause autism).
However, there has been a lot of speculation about the causes of autism by researchers and worried parents – which means that the issue has been widely studied. The vaccines’ role has been questioned a lot of times. Also, other potential risk factors of autism spectrum disorder have been too, such as environmental factors, advanced parental age, and genetic predisposition for ASD.
One of the most common speculated causes of ASD is vaccines. A lot of people have started asking the researchers “Do vaccines cause autism?” due to the simultaneous increase of the autism rates and vaccinated children. However, there has been a lot of research regarding the topic by physicians, scientists, and other health researchers. Every study so far has shown no link between autism and vaccines. But, there are still too many people who are not entirely sure whether vaccines cause autism. This is the reason why medical and public health establishments continue with researching the vaccines’ role in the development of ASD.
The MMR Vaccine Speculation
Questioning whether vaccines cause autism is dating back to the 1990s. A group of researchers from the UK published a study in 1995 in The Lancet. It was stated in the study that individuals who have received the MMR (measles-mumps-rubella) vaccine are more prone to developing bowel disease compared to those who haven’t received the MMR vaccine.
Andrew Wakefield, a gastroenterologist, was one of the researchers. He was the one that went a bit further studying a possible link between bowel disease and vaccines. Wakefield speculated that the vaccine virus is capable of disrupting the intestinal tissue which later led to neuropsychiatric disease (in this case autism) and bowel disease. This wasn’t the first time vaccines were associated with ASD, it was suggested by a few other researchers previously. Fudenberg, for example, published a small pilot study in a journal that wasn’t mainstream at the time a similar connection between the two. Gupta did the same, but he also reviewed possible treatments for the condition. However, when Wakefield began to interrogate the hypothesis, it wasn’t systematically investigated yet.
Wakefield and his 12 co-authors published a case series studies in 1998 in Lancet. They claimed that they found important evidence which led people to ask themselves “Do vaccines cause autism?” The group studies 12 cases and stated that there was evidence of the measles virus in children’s digestive systems, but particularly in kids with autism symptoms after they received MMR vaccines. The group was not able to demonstrate the relationship between autism and MMR vaccination in the paper they stated. However, he suggested a causal relationship between the autism and MMR vaccine in a video released along with the publication. He stated that there’s a higher risk to develop autistic enterocolitis if a child gets the MMR vaccine instead of the single vaccines. Wakefield also suggested switching from the combined MMR vaccine to single shots that a child should take over time. All of this becomes sketchier when you find out that he filed for a patent for a single-antigen measles vaccine back in 1997.
There was an immediate reaction to the Wakefield’s publication. The media showed the study to the world and parents became frightened. This later led to delaying or completely refusing to vaccinate the children. The usage of MMR vaccines has dropped substantially in the United Kingdom.
The possibility of a connection between autism and MMR has been studied constantly over the next twelve years. However, no relevant and reputable study had the same result as the Wakefield’s. There’s not even a single well-designed study that found any links between autism and MMR or bowel disease and MMR – confirming that there’s no reason to think that vaccines cause autism.
Dr. Richard Horton was the editor of the Lancet in 2004. He stated that Wakefield was obliged to inform the journal that he was getting paid by lawyers who were looking forward to suing the vaccine manufacturers at the time. Horton also noted that the research Wakefield has done was fatally flawed in his interviews. Almost all the co-authors of the study retracted their contribution to the study. The Lancet finally retracted the study in 2010, too.
Wakefield was banned from practicing medicine in the UK by Britain’s General Medical Council in May 2010, only three months after the retraction. The council also stated that Wakefield potentially harmed the health of the children with his research. Also, Wakefield’s involvement with the attorneys who were hoping to sue vaccine manufacturers was mentioned by the council.
After the Retraction
A British journalist, Brian Deer, published a report in the BMJ on January 6, 2011. He was also reporting flaws in Wakefield’s study previously. Deer concluded that Wakefield committed research fraud. The journalist talked to parents of the children from the study and found that the data about children’s conditions were falsified.
To be more specific, the evidence Wakefield provided was saying that 8 out of the 12 children who were examined showed autism-like and gastrointestinal symptoms only a few days after vaccination. But, the records showed that only two kids had these symptoms at this time frame. Also, the records showed that at least two kids had brain development delays even before the study even began. Wakefield claimed that all of the 12 children “seemed normal” before they took the MMR vaccine.
Deer examined the records of all the children who were studied. He noticed that the paper’s statements are not matching any numbers from the records in the following categories: the children who showed some symptoms only a few days after they took the MMR vaccine; those with non-specific colitis; and the children who had regressive autism. Six children in total had all of these symptoms according to the Lancet paper. However, not a single child did, according to the records.
Fiona Godlee was the editor of the BMJ at the time. She, with two other co-authors, Harvey Marcovitch and Jane Smith, examined the damage done to the public health in an accompanying editorial. They did a small study with no control group. It turned out to be almost completely fraudulent, but it still has a huge impact even today.
Scientists have discredited Wakefield’s numerous times by now. Besides, the evidence against the original study is too strong, and many experts suggest that the study shouldn’t have been published at first because it was poorly conducted. Also, finding out that the study was a research fraud adds more reasons not to believe that vaccines cause autism.
The Thimerosal Speculation
People who suspect that vaccines might be causing autism targeted for scrutiny of other vaccine components and other vaccines besides MMR. The controversy about the MMR vaccine died down a couple of years later, and critics started to question a new vaccine ingredient – thimerosal. It is preservative that contains mercury and it is used in some vaccines. However, this ingredient is not used in MMR because live vaccines don’t have antimicrobial agents in them.
Environmentalists, public and medical health workers, and lawmakers became very concerned about mercury exposure in the environment in the 1990s. They were particularly concerned about the mercury we get by consuming fish. The potentially harmful effects of mercury exposure were already known at the time. This is why the U.S. FDA (Food and Drug Administration) requested that amounts of mercury need to be reported in all of the products. The vaccines contained more mercury that could be found in fish than the FDA guidelines were approving. This type of mercury is taking the form of methylmercury – a type of mercury which is not excreted and metabolized in the body. If an individual is under high levels of exposure, this type of mercury could have harmful effects on the nervous system. However, thimerosal has a type of mercury that can metabolize in the body, to ethylmercury, to be more specific. It is thought that this compound has a lot less harmful effects than methylmercury. The compound is not widely studied at the time.
The Food and Drug Administration had problems with determining what should be the recommended levels of ethylmercury. Could methylmercury guidelines be applied to ethylmercury too? Do vaccines cause autism due to the mercury ingredient in them? They didn’t have an immediate solution to these problems. So, the FDA cooperated with the American Academy of Pediatrics and contacted vaccine companies to eliminate or just reduce the thimerosal from vaccines. Besides, there are a couple of planned studies ready to investigate if the mercury in vaccines has any potentially harmful effects in children exposed to it.
Activists are very concerned about the thimerosal in vaccines at this point. It is now thought by a lot of people that the mercury in vaccines is the cause of autism. However, there is no formal proof of this. The Institute of Medicine is currently reviewing this issue and whether the compound is safety. The first report published by the institute was in 2001. It is noted in this report that there is no enough evidence to reject or support any specific relationship between autism and mercury in vaccines.
However, the institute published its final report in 2004. It was concluded that a lot of evidence about the subject was gathered and that almost all of it was rejecting the thimerosal association with the development of neurological diseases. A lot of studies were done after this report was published, and the evidence is still showing no link between the mercury in vaccines and autism.
However, due to the unknown effects of the mercury in vaccines, almost all childhood vaccines don’t have thimerosal in them anymore. Still, some influenza vaccines contain some doses of it.
Baby Planet Overview
So, do vaccines cause autism? The answer is simple – no. There is no formal proof that is pointing at this, only rumors that. The parents whose children, unfortunately, suffer from ASD sometimes try to blame the vaccines for their child’s unfortunate condition. However, this is not a reason for you to stop vaccinating your kids due to the many benefits vaccines have on our lives.
Also, a child that is not vaccinated will harm the group immunity of other kids. This will put in danger other children as well as an unvaccinated child. The best researchers in the world have worked on vaccines for decades to provide us with the best possible treatment we have today. Without vaccines, we would probably have a lot shorter life span and we would be sick much more often. People sometimes believe that vaccines are a part of a global conspiracy, but without them, our lives would be much different.
- Vaccines and Autism: A Tale of Shifting Hypothesis, ncbi.nlm.nih.gov