At least 3% of measles cases this year were in people who were fully vaccinated, CDC says

MGN

At least 3% of measles cases confirmed so far this year have been in people who received two doses of the measles vaccine, meaning they were fully vaccinated, the Centers for Disease Control and Prevention says.

About three dozen of the nearly 1,200 measles infections in 2025 have been in people with two vaccine doses, the agency said Friday in its weekly update on cases. An additional 2% of cases were in people who received at least one dose of the measles vaccine.

Many of the cases were in Texas, which on Tuesday counted a 21st confirmed measles case in someone with at least two doses of the vaccine.

The first 20 cases did not result in hospitalizations, Lara Anton, a spokesperson for the Texas Department of State Health Services, said Monday. Those cases were in children 8 years old or younger.

Anton did not immediately respond to a request for more information about the additional case, which was reported on Tuesday after she spoke to CBS News.

The first 20 cases also did not include people who received their second dose as a result of post-exposure prophylaxis, Anton said. Post-exposure prophylaxis is offering someone a drug or vaccine after they are exposed to a germ, to reduce the chance they will be infected or develop severe disease.

The CDC says people exposed to measles can get vaccinated within 72 hours of when they were first exposed, if they are not fully immunized.

“If administered within 72 hours of initial measles exposure, MMR vaccine might provide some protection against infection or modify the clinical course of disease,” the agency’s recommendations say.

Texas has seen a deadly outbreak of the highly contagious virus this year. While cases there have recently slowed, CDC officials have said that authorities have been tracking more outbreaks in other communities across the U.S. linked to travel outside and inside the country.