Between January 1 and April 4, 2025, the Centers for Disease Control and Prevention (CDC) has been notified of 607 confirmed U.S. cases of measles in 22 jurisdictions and six outbreaks (defined as three or more cases), with the largest outbreak in Texas and New Mexico accounting for more than 90% of cases. Most of these cases were among children and adolescents who had not received a measles vaccine or whose vaccination history was unknown. Three measles deaths have been reported so far this year: one in an unvaccinated adult in New Mexico and two in unvaccinated school-aged children in Texas.
Measles is extremely contagious and begins with fever, cough, coryza (runny nose), and conjunctivitis (pink eye), followed 2–4 days later by a rash that starts on the face and spreads downward on the body. Infected people are contagious from 4 days before the rash starts through 4 days afterward. The virus is transmitted by direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes and can remain infectious in the air and on surfaces for up to 2 hours after an infected person leaves an area. Measles can cause severe health complications, including pneumonia, encephalitis, and death. Measles-mumps-rubella (MMR) vaccination remains the best way to protect against measles and its complications. Learn more on cdc.gov.