VACCINE AFFECT

This page examines a 2005 population-based study from Japan that tracked autism incidence before and after the withdrawal of the MMR vaccine. Alongside a summary of the study’s design and findings, it brings together key methodological critiques and contextual considerations that shape how this evidence is interpreted within the wider autism–vaccine literature.

This study examined whether trends in autism diagnoses over time were associated with changes in MMR vaccination rates or exposure to measles virus.Rather than comparing vaccinated and unvaccinated individuals, the researchers analysed population-level trends in autism diagnoses and MMR uptake. The researchers used an ecological time-trend design. They examined autism diagnosis rates across different birth cohorts and time periods.

This study examined whether children who received the MMR (measles, mumps, rubella) vaccine were more likely to be diagnosed with autism or other pervasive developmental disorders (PDDs) than children who did not receive the vaccine.