Rare breakthrough infections are expected with a vaccine that is about 97% effective, and state figures show most cases are still in people without a recorded measles vaccination.
Kentucky has recorded its first 2026 measles case in a person who had received two doses of the measles, mumps, and rubella (MMR) vaccine, according to Kentucky Department for Public Health (KDPH) figures reported by WKYT on September 21. The state's 2026 total rose to 53 confirmed cases, up from 50 on September 16, and Carroll County reported its first case in the current outbreak. The KDPH dashboard is updated on weekdays and may show newer totals.
