MMR vaccine does not cause autism

Wakefield’s study of 12 children with autism, which he fraudulently claimed was associated with autism, was withdrawn by The Lancet in 2010. The myth of the MMR vaccine causing autism has nonetheless persisted in anti-vaccine pockets world-wide despite mounting evidence to the contrary. Denmark is a small country with excellent health records. A 1991–1998 Danish study, which showed no association between the MMR vaccine and autism, was criticised for ignoring children at high-risk for autism. A second Danish nationwide cohort study of the MMR vaccine and autism in 657 461 children born between 1999 and 2010 specifically looked at children at increased risk of autism, for example, those with a sibling with autism. They captured over 5 million person-years of follow-up, during which time 6517 children were diagnosed with autism (1.0%). MMR-vaccinated children were no more likely than MMR-unvaccinated children to develop autism (hazard ratio 0.92, 95% confidence interval 0.85–1.02, (Fig. 1)). No increased risk of autism was observed in subgroups at increased risk, including those with a sibling with autism. An accompanying editorial discusses whether there is any value in further studies and suggests strategies to deal with vaccinehesitant parents. References