Concerns about a potential link between the MMR vaccine and autism have persisted for two decades, since a controversial and ultimately retracted 1998 paper claimed there was a direct connection.
Researchers in Denmark conducted a nationwide study of all children born to Danish mothers between 1999 and 2010.
Comparing children who received MMR vaccine with those who did not receive it, researchers calculated a fully adjusted autism hazard ratio of 0.93 (95% CI, 0.85 to 1.02) - meaning the MMR vaccine was not associated with an increased risk for autism.
"We have not found any confirmation of the theory that MMR vaccination increases the risk of autism", said researchers at the American Journal of Internal Medicine. Researchers hope a new study will again reassure parents vaccines are safe. Over the previous year, there has been a 30 percent increase in measles cases worldwide and deadly outbreaks in areas with large amounts of unvaccinated children. These individuals, more commonly known as anti-vaxxers, are drawing criticism at a time when there is a concerning increase in measles cases in Europe and the US.
Get push notifications with news, features and more. Today, vaccination rates are decreasing significantly in many parts of the world, with more and more children becoming sick and dying as a result.
Children aged six-11 months, travelling to other countries and regions where measles outbreaks are reported, are recommended the MMR vaccine. It is recommended before global travel that infants 6-11 months of age receive one dose of the MMR vaccine; children 12 months of age and older should receive two doses of the MMR vaccine, separated by at least 28 days; and teenagers/adults who do not have evidence of immunity against measles should get two doses of the MMR vaccine separated by at least 28 days.
There was no evidence of a link, or of "clusters" which suggested the jab was having an effect - and children who had the jab were very slightly less likely to be autistic.
In recent years, the anti-vaccination movement has become more and more mainstream globally, with many citing the supposed risk of autism as a reason for not vaccinating their children.
They said that doctors and public health officials needed to firmly label the association "a myth".