Measles (rubeola) is a highly contagious disease with significant morbidity/mortality. Measles-MumpsRubella (MMR) is a live-attenuated vaccine used in the United States (US) since the early 1970s to prevent measles infection. This retrospective longitudinal cohort study examined childhood MMR vaccination effectiveness (VE) on preventing diagnosed measles cases | Childhood MMR vaccination and the incidence rate of measles infection: A ten year longitudinal cohort study of American children born in the 1990s