AUTISM SCIENCE IN THE NEWS – Does the Measles-Mumps-Rubella (MMR) Vaccine Cause Autism?

A review of routine vaccinations for children says NO.

The 1998 publication of a study by the British researcher (Andrew Wakefield) in the journal Lancet resulted in great concern among some parents and clinicians that the MMR vaccine causes autism.

This concern caused many parents to withdraw administration of the MMR vaccine to their children and the resulting increase the childhood diseases (measles, mumps, and rubella) for which the immunizations were sought.

The MMR-Autism link, however, was debunked by multiple subsequent studies. Furthermore, in 2010, the Wakefield article was retracted by Lancet upon revelations of methodological and ethical problems in the conduct of the study.

A recent review of the safety of several routine vaccinations for children confirms the many earlier articles that reported no association between MMR and autism (Maglione MA et al, Pediatrics, 2014;134:325). We annotate here data from well-controlled studies cited in the Pediatrics review indicating strong evidence against a relationship of MMR vaccinations and autism. No study indicating a positive relationship was found.

One study was population-based, drawing from the Danish Civil Registration System from January 1991 to December 1998 (Madsen KM et al, NEngJMed, 2002; 347:1477-82). There were 537,303 children in the cohort. 316 children had received a diagnosis of autistic disorder, 422 received a diagnosis of another autistic-spectrum disorder. The risk of autism was not different between the vaccinated and the unvaccinated groups.

A second matched case-control study was conducted by investigators in Poland (Mrozek-Budzyn D et al, Pediatr Infect Dis J; 29:397-400). The sample included children aged 2-15 years old; 96 had autism; 192 did not. For children vaccinated before the diagnosis, the risk for a physician-diagnosed autism was lower than in the non-vaccinated group. There was also no difference in risk for autism when the comparison was made between those who received the combination MMR and those who received the measles vaccine only.

A third study, also using the matched case-control method, used the United Kingdom General Practice Research Database (Smeeth L et al, Lancet, 2004:364:963-969). 1010 cases had MMR vaccination before they were diagnosed with autism; controls were 3671 children who did not receive a diagnosis before their matched case was diagnosed. The odds ratio for an association between MMR and autism (pervasive developmental disorder) was significantly less than 1 indicating the absence of a relationship.

A fourth study, by Japanese researchers, that used the case-control method, is the first conducted in Asia (Uno Y et al, 2010;30:3042-46). There were 189 cases with ASD; 224 controls were volunteers from general schools. No significant differences in the presence of ASD was found according to MMR vaccination or the number of vaccine injections.

Scientific evidence does not justify withdrawal of MMR vaccinations for preventing autism spectrum disorder.