As measles cases rise, more people are wondering if they’re sufficiently protected against the disease.
The good news, experts said, is that most Americans don’t need a booster — especially those who received two doses of the measles, mumps, and rubella (MMR) vaccine, which is 97% effective against measles.
Even for those who received just one dose of the MMR vaccine — those vaccinated between 1968 and 1989 — the vaccine is still 93% effective against measles.
And people born before 1957 probably have ample protection, as they are assumed to have natural immunity due to widespread measles exposure, experts said.
“For adults, there are currently no recommendations to get another measles shot,” David DiJohn, MD, a pediatric infectious diseases physician at the University of Nevada Las Vegas, told MedPage Today.
There are some groups, however, who may be at risk and who may benefit from a dose of the current MMR vaccine. Chiefly, this group includes people born after 1957 and vaccinated before 1968.
A single-dose inactivated measles vaccine used from 1963 to 1967 was later found to not be as effective or long-lasting as the currently used live-attenuated vaccine, experts said.
“Anyone who received an inactivated vaccine between 1963 and 1967 is recommended to receive a dose of the current MMR vaccine,” said Andrew Handel, MD, a pediatric infectious disease physician at Stony Brook Medicine in New York.
Another group of people who may want to consider a measles booster are those in regular contact with people ineligible for the MMR vaccine, said James Cutrell, MD, an infectious disease specialist at UT Southwestern Medical Center in Dallas. Unvaccinated pregnant women and people who are immunocompromised rely on others to stay safe against the virus.
Finally, healthcare workers should have two documented doses of MMR vaccine, according to a recent CDC Health Alert Network advisory about measles.
The CDC advisory also recommends that adults who aren’t at high risk of exposure still have at least one documented dose of MMR or other evidence of immunity, much as a positive measles immunoglobulin G (IgG).
“If a patient is unsure of whether they have received the full measles vaccine series or whether they have had a natural measles infection, they can consider checking a measles titer to clarify if they should receive a measles vaccine,” Cutrell said.
However, if there are no medical contraindications, it’s not unreasonable for someone to get a booster shot just to be safe, Handel said.
“There’s not a major downside to an MMR vaccine in a healthy person,” DiJohn added. “It probably doesn’t do any significant harm for someone to get another MMR dose.”
Measles was declared eliminated from the U.S. in 2000, indicating a lack of continuous spread for greater than 12 months. This was achieved by both a highly effective U.S. vaccination program as well as better measles control in the Americas, according to the CDC.
From 2000 to 2013, the number of annual measles cases rose above 200 just once, to 220, in 2011. Since then, however, cases have reached several high water marks, including 667 in 2014 and 1,274 in 2019. After a pandemic-related lull, cases rose to 285 last year, and have already totaled 301 in 2025, according to CDC data.
Indeed, the U.S. just had its first measles death since 2015, which was soon followed by a second measles death. One occurred in an unvaccinated child, and the other in an unvaccinated adult.
While HHS Secretary Robert F. Kennedy Jr. has issued a lukewarm endorsement for getting vaccinated against measles, he has also continued to cast doubts about the shot. He told Fox News in two interviews earlier this month that the vaccine “causes deaths every year” and “causes all the illnesses that measles itself causes, encephalitis and blindness.” He also said the vaccine “wanes about 4.5% per year, so that means older people are essentially unvaccinated.”
Paul Offit, MD, said these statements were incorrect, and clarified a number of Kennedy’s statements about measles and vaccination in a separate video for MedPage Today.
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