## Hoax #4: Vaccines cause autism

Probably the best known vaccine myth is the claim that vaccines cause autism. This stems primarily from an article by Wakefield and his team published in the prestigious medical journal The Lancet in 1998. Children with autism are characterised by repetitive behaviour, sensitivity to sound, and an inability to interpret emotions. These children also seek solitude, avoid eye contact, and do not respond when their name is called. The main cause of this disease are genetic factors (gene variants or mutations), but environmental factors (e.g., advanced parental age, epigenetic changes, pollution) are also thought to have an influence. However, Wakefield and his team believed that the MMR (a triple vaccine against three viral diseases Measles, Mumps and Rubella) vaccine could also cause autism and claimed to have demonstrated a causal link between the measles vaccine, which is part of the MMR vaccine, and autism in eight children. In addition, they presented the mechanism by which this vaccine causes autism, where they claimed that the measles virus from the live vaccine, when it enters the body, causes inflammation of the gut. Damaged intestinal walls then release harmful proteins into the blood, which then enter the brain where they cause changes that lead to autism. This whole process sounds more credible precisely because it was published in a prestigious scientific journal. The problem, however, is that this is the only study that supposedly "proves" the link between vaccines and the development of autism. On the contrary, since the publication of this paper, dozens of independent studies have been conducted on hundreds of thousands of children that refute any negative effect of vaccines in relation to the development of autism. Eventually, even the study by Wakefield and his team was retracted, i.e., labelled as untrue.

Vaccination opponents still believe that the MMR vaccine causes autism because it is given to children at a similar age when the first symptoms of autism appear. However, this assumption is flawed and only suggests that these phenomena are correlated, not causally related. Moreover, there are dozens of studies that refute that vaccines cause autism. Consequently, all the above facts confirm that vaccines do not cause autism.