Do I Need a Measles Shot at My Age?

2. Many older adults have immunity — but some may need the vaccine

With the current outbreak, you might be wondering: Do I need the measles vaccine?

If you’ve had measles — and you probably have if you were born before 1957, the CDC says — it’s unlikely you’ll get it again. You’re also considered immune if you’ve had the two-dose MMR vaccine, given for measles, mumps and rubella. According to the CDC, two doses of MMR is about 97 percent effective at preventing measles — and that protection lasts a lifetime.

However, people vaccinated before 1968 and those vaccinated between 1968 and 1989 may need an additional dose of MMR, says Robert H. Hopkins, Jr., M.D., medical director of the National Foundation for Infectious Diseases. That’s because some adults may have been given a less effective vaccine that was administered in the ’60s before MMR was available, or some may have received only one dose of MMR initially. (One dose of MMR vaccine is 93 percent effective against measles, the CDC says.)

If you can’t remember whether you’ve had the illness or two shots of the MMR vaccine, talk to your doctor. The CDC says there is no harm in getting another dose of the vaccine, even if you have prior immunity. Your doctor can also test your blood to determine whether you’re immune, though the CDC says this is generally not recommended.

This is especially key if you plan to travel internationally. The CDC says, “Travelers who are unsure if they or their travel companions are fully protected against measles should schedule an appointment to see their clinician at least six weeks before traveling so that they have enough time to get fully vaccinated.”

Hopkins notes that immunocompromised or pregnant people should not receive the measles vaccine. The CDC says travelers who are unable to safely receive a measles vaccine should talk to their doctor and consider postponing their trip.

Keep in mind that no vaccine is 100 percent effective, and about 3 out of 100 people who are fully vaccinated for measles will get it if exposed to the virus, the CDC says. Fully vaccinated people who get measles typically experience milder symptoms and are less likely to spread the disease to other people.

“The best defense against measles is vaccination,” Hopkins says.

3. Without population immunity, measles can spread

Because the virus spreads so easily, you need a high level of immunity in the community — or about 95 percent of the population immunized — to prevent ongoing transmission, says John Schieffelin, M.D., an infectious disease physician and associate professor of pediatrics at Tulane University School of Medicine in New Orleans. 

Research shows that the U.S. is under that threshold. During the 2023–2024 school year, MMR vaccination coverage among kindergartners was 92.7 percent, down from 95 percent in pre-pandemic years, according to CDC data. This translates to roughly 280,000 kindergartners who are at risk for measles. In some states, measles vaccine coverage among children is under 85 percent.

Vaccine misinformation is partially to blame for this dip, Stinchfield says. So is the pandemic, since many nonurgent doctor’s appointments were skipped or delayed, and so routine vaccinations were missed. (The first dose of the MMR vaccine is typically given around the first birthday; the second dose is around kindergarten entry.) 

If vaccination rates continue to decline, measles could reestablish itself in the U.S., health experts warn. “Any kind of drop in our vaccine rates, we need to pay attention to and get them back up where they belong,” says Stinchfield, who adds that grandparents can help play a role by talking to their children and grandchildren about vaccines.

4. Measles can be dangerous, even deadly

Schieffelin says a common misconception is that measles isn’t a big deal, since virtually everyone used to get infected. But that is not the case.

Common symptoms — which include fever, cough and runny nose — can cause a person to feel “miserable,” says Stinchfield, who helped take care of hospitalized children during a large measles outbreak in Minnesota in the 1990s.

Three to five days into the illness, a rash breaks out and spreads from the top of the head down the body. At this point, a fever can spike to more than 104°F, the CDC says. 

The thing with measles, though, is that it’s not uncommon for the illness to turn severe. About 1 in 5 unvaccinated people in the U.S. who get measles end up in the hospital, according to the CDC. Complications range from dehydration to pneumonia to encephalitis, or swelling of the brain. 

Measles can also mess with your immunity to other illnesses, Stinchfield says — a phenomenon called immune amnesia.

Young children are at increased risk for these complications; so are older adults, Schieffelin says. “As we get older, we don’t tolerate [viruses] quite as well,” he says.

It’s estimated 136,200 people worldwide, mostly children, died from measles in 2022, according to a report from the CDC and the World Health Organization.

5. Unvaccinated travelers can spread measles

Most people in the U.S. are protected against measles with the vaccine, but the virus hasn’t been eliminated worldwide. In fact, the global vaccination rate for both MMR doses hovers around 74 percent, according to the CDC. In some countries, it’s as low as 66 percent.

An unvaccinated traveler who picks up a case in another country can bring it to the U.S. and spread it to other unvaccinated people, Stinchfield says. In a community with low vaccination rates, the disease will spread like wildfire, she adds.

Measles “is still out there,” Schieffelin says. “And by not being vaccinated, you really do run the risk of getting sick as well as your family members getting sick.”

Editor’s note: This story, first published Jan. 24, 2024, has been updated to include new information.