Measles continues to spread across the United States, with confirmed cases in 34 jurisdictions as of June 5 and two deaths reported in unvaccinated children.
Measles is a highly contagious and potentially life-threatening disease—it is considered one of the most contagious diseases in humans.
“It’s transmitted by infected respiratory droplets: If somebody is talking, coughing, sneezing, they can spread these droplets,” says Dr. Tina Tan, an infectious disease specialist, professor of pediatrics at Northwestern’s Feinberg School of Medicine, and president of the Infectious Diseases Society of America.
These droplets can linger in the air for two hours, Tan says, so if somebody is exposed to those droplets and they’re not vaccinated, “they’re at very high risk of becoming infected.”
That’s why getting vaccinated against measles is so important: The measles, mumps, rubella (MMR) vaccine is the best way to prevent measles.
We spoke to Tan and another infectious disease expert to answer common questions about the MMR vaccine. Here’s what they said.
How does the MMR vaccine work?
The MMR vaccine protects against three serious infections: measles, mumps, and rubella. Two doses of the MMR vaccine are 97 percent effective against measles and 86 percent effective against mumps, and one dose is 97 percent effective against rubella.
Is the MMR vaccine safe for children?
Yes. “The vaccines that we use today are very safe and very effective,” says Tan.
Several studies have shown that the benefits of the MMR vaccine outweigh any very rare potential risks. The most common side effects include a fever, temporary joint pain, and soreness, a rash, or redness where the vaccine was given.
On the other hand, contracting measles can lead to many health problems, including severe diarrhea, pneumonia, deafness, blindness, and brain swelling. “It’s actually one of the most severe illnesses that a person can get,” adds Tan.
When was the MMR vaccine introduced?
The MMR vaccine was first introduced in the 1960s. However, Dr. Charles G. Prober, professor of pediatrics, microbiology, and immunology at Stanford University, explains scientists have refined the vaccine, and it has become more effective over the years.
In the decade before the vaccine was available, there were 500 measles-related deaths in the U.S. every year. Now, the vaccine has made measles rare in the U.S. In fact, the disease was eliminated in the U.S. in 2000. And globally, measles vaccination prevented more than 60 million deaths between 2000 and 2023.
Why is it so important for children to get the MMR vaccine?
As the ongoing measles outbreaks in the U.S. have shown, it’s vital to vaccinate children to protect them against the disease and potentially life-threatening problems.
Additionally, some people, including those receiving chemotherapy or those who are immunocompromised, can’t get the MMR vaccine, explains Prober.
Prober says getting vaccinated helps protect people who can’t get the shot—like infants or those with certain health conditions—and who are more likely to get seriously sick. When the majority of people get vaccinated, “children that are immunocompromised will be protected because everybody around them will not pick up the virus and spread it to them,” he says.
Is there any other way to prevent measles?
No. Even though Health and Human Services Secretary Robert F. Kennedy Jr. has promoted the use of vitamin A to prevent measles, experts, including Tan and Prober, confirm that vitamin A does not prevent measles and that the MMR vaccine is the best way to protect against measles.
“There is no treatment, and there is no cure,” Tan adds. “People that are saying that vitamin A, and cod liver oil, and inhaled steroids, and antibiotics are the way to cure measles [are] incorrect.”
When should children get the MMR vaccine?
Children should get two doses of the MMR vaccine: the first dose between 12 and 15 months and the second dose between 4 and 6 years.
However, if your child is older than the recommended ages and hasn’t been vaccinated or is missing a dose, they can still get it.
“It’s never too late in life for a measles vaccine,” Prober says.
If a person didn’t get vaccinated, Tan adds, they can get two doses closer together as long as they are given 28 days apart.
“You can basically accelerate the schedule that way and get your child fully vaccinated,” she says. The CDC also says that people traveling internationally should be fully vaccinated before traveling. This means that babies between 6 and 11 months old should get 1 dose of the MMR vaccine before traveling, and still get two more doses after they’ve turned 1.
For more information, talk to your health care provider.
This article is supported by the Centers for Disease Control and Prevention of the U.S. Department of Health and Human Services (HHS) as part of a financial assistance award to the CDC Foundation totaling $69,392,486 with 100 percent funded by CDC/HHS. The contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement, by CDC/HHS, or the U.S. Government. In addition, the CDC Foundation does not guarantee and is not responsible for the accuracy or reliability of information or content contained in this article. Moreover, the CDC Foundation expressly disclaims all liability for damages of any kind arising out of use, reference to, or reliance on any information contained within this article. This article are not intended as, and should not be interpreted by you as, constituting or implying the CDC Foundation’s endorsement, sponsorship, or recommendation of the information, products, or services found therein.