Adults who received the measles vaccine from 1963 to 1967 should consider another MMR dose if they have not already had one, experts say, because that version was not considered fully effective. People with records of two doses after their first birthday are considered protected.
Adults unsure of their vaccination history can check their state immunization registry or ask a provider or pharmacist. If records cannot be found, Dr. Gavin Harris said public-health guidance is to get an MMR dose; Walgreens immunization director Samantha Picking said an extra dose is safe even if someone already received two. Harris said two doses are about 97% effective at reducing infection, compared with about 93% for one. Picking said adults born before 1957 are considered immune.
The article reports 3,471 U.S. measles cases and four measles-related deaths this year. Harris said adults account for about 38% to 40% of this year's cases and just over half of measles hospitalizations in 2025. For unvaccinated people exposed to measles, Dr. Geeta Sood said a vaccine within three days or IVIG within six days can protect against illness.
