More evidence MMR vaccine does not cause autism, even in at-risk children
New research published in Annals of Internal Medicine provides further evidence that there is no connection between the measles, mumps, rubella vaccine and autism, even in children with other risk factors for the condition.
“The hypothesized link between the measles, mumps, rubella (MMR) vaccine and autism continues to cause concern and challenge vaccine acceptance almost two decades after the controversial and later retracted Lancet paper from 1998, even though observational studies have not been able to identify an increased risk for autism after MMR vaccination,” Anders Hviid, DrMedSci, from Statens Serum Institut, Copenhagen, Denmark, and colleagues wrote.
Vaccine hesitancy has been recognized by the WHO as one of the top 10 threats to global health in 2019. Cases of measles has increased 30% globally, according to WHO, and in January, Washington declared a state of emergency after 34 people were infected with measles due to anti-vaccine fervor.
Social media has notably played a role in the anti-vaccine movement and outlets, such as YouTube, are now taking action by blocking anti-vaccine ads.
Hviid and colleagues investigated the association between MMR vaccine and autism in a more recent and larger cohort of children from Denmark over a longer duration of time.
The researchers studied 657,461 children born in Denmark between 1999 and 2010. Participants were followed from 1 year of age through Aug. 31, 2013.
Data on MMR vaccination, autism diagnoses, other childhood vaccines, sibling history of autism, and autism risk factors were linked to children in the study cohort using Danish population registries. The analysis was adjusted for age, birth year, sex, other childhood vaccines, sibling history of autism and autism risk factors.
Autism was diagnosed in 6,517 participants (incidence rate, 129.7 per 100,000 person-years).
The fully adjusted HR for autism was 0.93 (95% CI, 0.85-1.02) in MMR-vaccinated children compared with MMR-unvaccinated children. Additionally, there was no increased risk for autism associated with MMR vaccination in subgroups of children with sibling history of autism, autism risk factors or other childhood vaccinations, or during certain time frames after vaccination, according to the researchers.
“A main reason that parents avoid or are concerned about childhood vaccinations has been the perceived link to autism,” Hviid and colleagues concluded. “Our study adds to previous studies through significant additional statistical power and by addressing hypotheses of susceptible subgroups and clustering of cases. We believe that our results offer reassurance and provide reliable data on which clinicians and health authorities can base decisions and public health policies.” – by Alaina Tedesco
Disclosures: Hviid reports receiving grants from Novo Nordisk Foundation. Please see study for all other authors’ relevant financial disclosures.