The extensive use of the measles-mumps-rubella MMR vaccine has allegedly overlapped with an increase in the frequency of autism in California. The measles virus used in the MMR vaccine is a live weakened virus that normally causes no symptoms or only very mild ones. However, wild-type measles can infect the central nervous system and even cause post infectious encephalomyelitis, probably because of an immune-mediated response to myelin proteins.
A population-based study of measles, mumps, and rubella vaccination and autism was conducted by the Massachusetts Medical Society asks the question: Is there a relation between MMR vaccinations and autism? The question could be answered by conducting several types of studies of sorting or developing data. The population was not well defined at the …show more content…
Follow-up of 5811 children was stopped before December 31, 1999, because of a diagnosis of autistic disorder, emigration, or other diseases. For children who received MMR vaccine, there were 1,647,504 person-years of follow-up, and for children who did not receive the vaccine, there were 482,360 person-years of follow-up. There was no association found between the development of autistic disorder and the age at vaccination. Overall, there was no increase in the risk of autistic disorder or other autistic-spectrum disorders among vaccinated children as compared with unvaccinated children. This study provides arguments against a causal relation among autism and MMR vaccination. First, the risk of autism was comparable in vaccinated and unvaccinated children. Second, there was no chronological clustering of cases of autism at any time after immunization. Third, both autistic disorders and other autistic-spectrum disorders were not associated with MMR vaccination. The results are from a nationwide prospective cohort study with nearly complete follow-up data, which was one of the study types discussed in the
A population-based study of measles, mumps, and rubella vaccination and autism was conducted by the Massachusetts Medical Society asks the question: Is there a relation between MMR vaccinations and autism? The question could be answered by conducting several types of studies of sorting or developing data. The population was not well defined at the …show more content…
Follow-up of 5811 children was stopped before December 31, 1999, because of a diagnosis of autistic disorder, emigration, or other diseases. For children who received MMR vaccine, there were 1,647,504 person-years of follow-up, and for children who did not receive the vaccine, there were 482,360 person-years of follow-up. There was no association found between the development of autistic disorder and the age at vaccination. Overall, there was no increase in the risk of autistic disorder or other autistic-spectrum disorders among vaccinated children as compared with unvaccinated children. This study provides arguments against a causal relation among autism and MMR vaccination. First, the risk of autism was comparable in vaccinated and unvaccinated children. Second, there was no chronological clustering of cases of autism at any time after immunization. Third, both autistic disorders and other autistic-spectrum disorders were not associated with MMR vaccination. The results are from a nationwide prospective cohort study with nearly complete follow-up data, which was one of the study types discussed in the