Gastañaduy PA, Funk S, Lopman BA, et al. - Researchers investigated factors related to measles transmission in the United States following eradication in a cross-sectional study carried out from January 1, 2001, to December 31, 2017. The study included US residents and international visitors with a confirmed diagnosis of measles. The primary factors related to measles transmission in the United States were lack of vaccination and birth on or after 1957, and assortative transmission by age, especially among school-aged children. The investigators' findings underline the importance of maintaining homogenous, high, two-dose measles vaccine coverage to sustain measles elimination in the United States, especially among school-age children.