Do vaccines cause autism? Biggest study yet once again dispels anti-vax theories
A new study from Denmark has provided the most compelling evidence yet that vaccines are not connected to autism. The study of more than half a million children found no link between the Measles Mumps and Rubella (MMR) vaccine and autism diagnosis.
Numerous studies have been conducted in the past dispelling the theory that vaccines cause or increase the risk of autism in children, but this has been the biggest yet.
The research carried out by the Staterns Serum Institut (SSI) in Denmark and published in the Annals of Internal Medicine involved 657 461 children born between 1999 and 2010. Of those children, 6517 were diagnosed with autism spectrum disorder.
"Autism occurred just as frequently among the children who had been MMR-vaccinated as it did among the 31,619 children who had not been vaccinated," says SSI’s Senior Scientist Anders Hviid.
Therefore, we can conclude that the MMR vaccine does not increase the risk of developing autism.
"We also focused on other risk parameters: children with old parents, children whose mothers experienced pregnancy-related complications, or children whose mothers smoked, children with low birth weight, as well as time-related associations between the time of MMR vaccination and development of autism. In none of the cases did we observe a higher risk of developing autism among the MMR-vaccinated children compared with the non-vaccinated children", says Hviid.
Researchers said the age at which the MMR vaccine is administered coincides with the age at which many children who develop autism begin first showing symptoms. This may explain why some parents of autistic children draw a link that the vaccine is what caused the autism to develop, despite there being no association.
The link between vaccines and autism was first made by Andrew Wakefield in a 1998 paper published in the Lancet. That paper was later formally retracted when it was found the author had falsified data and had a “fatal conflict of interest” when conducting the research.
It was also discovered that Wakefield’s research had been partially funded by lawyers who hoped to sue vaccine manufacturers on behalf of parents of children with autism.
But it was all too late. Vaccination rates had already started to plummet and still today, some so-called ‘anti-vaxers’ continue to believe that vaccinations cause autism.
Since the MMR vaccine was introduced in Australia the number of children catching measles, mumps and rubella has fallen to very low levels, although some adults who were not immunised as children remain at risk of catching these illnesses. The introduction of the vaccine has also led to a drop in the number of babies born with serious disabilities caused by their mothers contracting rubella in the early stages of pregnancy.
The first dose of the MMR vaccine is likely to give 93 percent of those receiving it immunity against measles, 78 percent against mumps, and 97 percent of people immunity against rubella. After the second dose, about 99 percent of recipients will be protected against all measles and rubella, and 88 percent against mumps.