1,024 cases of measles have been confirmed in the US as of May 15, 2025. Given this rise, we’ve fielded lots of questions about the virus and the Measles, Mumps and Rubella (MMR) vaccine. Let’s dig into this topic a bit further!
We’ll first start with the confirmed cases, the cases are equally spread amongst all age groups (under 5 years of age, 5-19 years of age, and 20 years and older), with the majority of the cases, 97%, reporting either an unvaccinated or unknown vaccination status. Out of all the cases, there is only one confirmed death and 1 other under investigation. It’s important to keep in mind that the US currently has 340.1 million people, so 607 confirmed cases are less than 1% of the population.
Measles is a high contagious viral illness that starts with a fever, cough, fatigue and runny nose, within 7-14 days after exposure small white spots with bluish-white centers will appear inside the mouth on the cheek. These are called Koplik’s Spots. People who suspect they have been exposed to the measles should contact their healthcare provider or an urgent care center immediately for care.
In 1963 the first measles vaccine was licensed for use in the US and was the first significant step in measles protection. Patients who were born before 1957 are generally considered to have a natural immunity to measles as most children contracted it and have formed a life-long immunity to it before that time. In 1989, an outbreak of the measles among school-aged children prompted a recommendation for a second dose of MMR vaccine for all children, which led to a further decline in reported cases, with the US declaring an elimination of measles in 2000 (an absence of the continuous spread for greater than 12 months).
The MMR vaccine is currently recommended to be given 2 doses of the vaccine with the first dose between the age of 12-15 months, and the second dose between 4 and 6 years old. Older children, adolescents and adults should only receive additional doses of the MMR if they do not have evidence of immunity. This evidence would be in the form of a laboratory titer test. Titer tests are blood tests that check for the presence of antibodies which indicate immunity to, in this case, the measles. This immunity can be either from a vaccination or from a past infection.
The CDC further explains that only people at increased risk during an outbreak should receive an additional dose of the MMR, and those people will be notified by public health authorities.
Further take aways include that no booster vaccine is recommended at this time, with the CDC stating that “people who received two doses of measles vaccine as children according to the U.S. vaccination schedule protected for life, and they do not ever need a booster dose”.
Finally, remember that good hand hygiene, staying home when sick, cleaning surfaces regularly, and overall good nutrition and rest can help keep you safe from any virus, including measles, mumps, and rubella!