Zucker JR, Rosen JB, Iwamoto M, et al. - In 2000, measles was declared eliminated in the United States; however, there was an outbreak of measles in New York City when one unvaccinated child returned home from Israel with measles. On September 30, 2018, 9 days after the child returned home, onset of rash occurred. With this in mind, researchers investigated suspected cases of measles via conducting interviews, assessing medical and immunization records, identifying exposed persons, and performing diagnostic testing. Using the Citywide Immunization Registry, they monitored the uptake of measles–mumps–rubella (MMR) vaccine (administered as either MMR or measles–mumps–rubella–varicella vaccine, and collectively referred to as MMR vaccine).  A total of 649 confirmed cases (median age of patients: 3 years) of measles were reported; onsets of rash occurred between September 30, 2018, and July 15, 2019. Most patients (93.4%) belonged to the Orthodox Jewish community, and 473 of the patients (72.9%) resided in the Williamsburg area of Brooklyn, NY. Among patients, no vaccination was reported in 85.8% with a known vaccination history. Pneumonia and hospitalization comprised the serious complications. Efforts to promote vaccination led to an increase in the percentage of children in Williamsburg who received at least one dose of MMR vaccine, from 79.5% to 91.1% among children 12 to 59 months of age. As of September 9, 2019, 559 staff members at the Department of Health and Mental Hygiene have been committed to the measles response. The Department of Health and Mental Hygiene response incurred $8.4 million. Outcomes thus indicate that the outbreak response was resource intensive and resulted in serious illness, especially among unvaccinated children.