A study of over 500,000 Danish children found no difference in autism rates between vaccinated and unvaccinated kids.

To make sure the vaccine was safe, researchers in Denmark tracked more than half a million children born over several years. They compared the children who got the MMR shot to those who did not. The risk of autism was exactly the same in both groups. The vaccine did not make kids more likely to develop autism, no matter what age they got the shot.