How to Protect Yourself and Others From Measles Outbreaks

As measles cases increase, the best way to protect yourself and others is vaccination.

“Measles is one of the world’s most contagious diseases,” says Hospital Epidemiologist Gabriela Andujar Vazquez, MD, who specializes in infectious diseases and international health at Dartmouth Hitchcock Medical Center. “But measles is almost entirely preventable through vaccination, which is both safe and highly effective.”

How well do vaccines work

Two doses of the measles, mumps, and rubella (MMR) vaccine is 97 percent effective in protecting you from the virus. One dose is 93 percent effective.

That means if you are exposed to the virus and you have one or two shots of the vaccine, you have a 93 percent or 97 percent less chance of getting measles than if you did not have one or two doses of the vaccine.

If you are vaccinated, not only do you dramatically reduce your individual risk, but even if you do get the virus, it will likely be milder and you are less likely to spread it.

Another benefit is that when vaccination rates are high, communities develop resistance to the spread of the virus.

“When more than 95 percent of people in a community are vaccinated, most people are protected through community immunity or what is called herd immunity,” says Andujar Vazquez.

A spike in measles cases, as vaccination rates drop

Yet, even with the vaccine’s success in eliminating the virus from the United States in 2000 and the fact that the MMR vaccine has few risks or side effects, vaccination rates are dropping.

At the same time, cases are rising.

“Vaccination rates across the U.S. have declined significantly. Most states are now below the 95 percent vaccinated threshold for kindergartners,” says Andujar Vazquez.

Meanwhile, New Hampshire’s vaccination rate for kindergarteners was about 89 percent for the 2023-2024 school year, and Vermont’s was 92.9 percent.

Tellingly, most of this year’s cases are among the unvaccinated.

In early March, an unvaccinated adult died in New Mexico. That followed an unvaccinated child’s death in Texas in February.

These deaths come amid outbreaks in Texas and New Mexico totaling some 208 confirmed cases as of March 7, 2025, according to the Centers for Disease Control and Prevention (CDC).

Over this same time, a total of 222 measles cases have been reported by twelve U.S. jurisdictions. These states include Alaska, California, Florida, Georgia, Kentucky, New Jersey, New Mexico, New York City, Pennsylvania, Rhode Island, Texas, and Washington. Most of these cases were among children who had not received the MMR vaccine.

“It all points to why vaccinations are so important,” says Andujar Vazquez.

How measles spreads

Understanding how measles spreads also can help protect yourself and others.

The virus is usually transmitted through respiratory droplets in the air or on surfaces, often after an infected person coughs or sneezes. 

The virus can remain active and contagious in these droplets for up to two hours after the infected person leaves an area.

If you get the virus

It is helpful to know what the symptoms are.

Typical symptoms include a fever above 100.4 F degrees or as high as 105.5 F, a cough, runny nose, red and watery eyes (conjunctivitis), and a rash.

After exposure to the virus, you typically will not get symptoms for 10 to 14 days, but symptoms can emerge anytime between seven and 21 days after infection.

The first symptom is usually a fever followed by a rash three to five days later. The rash typically begins on the face and neck before spreading downward to the body, arms and legs.

Measles patients are advised to wear masks and be isolated while contagious, which is typically four days before the rash starts and four days afterward.

There is no specific treatment or antiviral therapy. Medical care is considered supportive only, meaning it can help relieve symptoms and address complications such as bacterial infections.

Most measles patients recover within a week, but measles can lead to serious complications, says the CDC. These include pneumonia, encephalitis, and death. Contact your healthcare provider immediately if you think you have the virus.

Do you need an MMR vaccine?

Determining whether vaccination is needed is based largely on presumptive evidence of immunity.

The CDC says presumptive evidence of immunity for measles can be determined by your health provider based on documentation of your vaccination history, lab tests, or whether you have had measles, which means you likely are immune.

Also important to consider is the measles vaccine did not become available until 1963. Some born between 1963 and 1967 received an inactivated vaccine (not a live measles vaccine) that has been determined not to be effective, but they also may have later got the live vaccine or had exposure to measles, both of which generally provide immunity.

MMR recommendations for those with no presumptive evidence of immunity

• Newborn children do not have presumptive immunity. It is recommended that they get a two-dose vaccine course with the first dose at 12 to 15 months and the second at four to six years of age. Children can receive the second dose earlier as long as it is at least 28 days after the first.
• College-aged students with no presumptive evidence of immunity should get two doses of MMR vaccine, separated by at least 28 days.
• Adults with no presumptive evidence of immunity should get at least one dose of MMR vaccine.
• Healthcare workers or international travelers with no presumptive evidence of immunity should get two doses of MMR vaccine.

Recommendations for those who have had a measles vaccine or measles itself

• If you were born before 1957, you likely have had exposure to measles and so have immunity.
• If you were born between 1957 and 1963, you would not have received a vaccine until 1963 or later. You are likely protected by either having had exposure to measles or by having the more effective “live” measles vaccine later in life.
• If you were born between 1963 and 1967, you are likely protected by either having had exposure to measles or having had a dose of the live measles vaccine once it became available.
• If you were born between 1968 and 1989, you likely received a single dose of the vaccine and are protected. But you should consider an MMR booster if you are in a high-risk group such as healthcare personnel, international travelers, and those in areas experiencing measles outbreaks.

3/11/25 update on measles in NH and VT

New Hampshire has not yet been impacted by the recent rise of cases, but on March 11, the Vermont Department of Health confirmed a case of measles in a school-aged child in Lamoille County. This is the first case of measles in Vermont in 2025, following two cases in 2024 and two cases in the decade prior, one in 2011 and one in 2018. This case is not related to the ongoing domestic outbreaks of measles in the United States or to the current measles outbreak in Québec. 

If or when an outbreak does occur in your community, your risks of getting measles if you are vaccinated remain very low, and your symptoms are likely to be less severe.

The NH Immunization Program (NHIP) is a vaccine resource for healthcare providers, schools, childcare providers, families, and the general public. The New Hampshire DHHS (Department of Health & Human Services), through the NHIP's Vaccines for Children (or "VFC") program, provides all the recommended vaccines for every child in the state, regardless of insurance or income. DHHS also urges individuals and caregivers to talk with their healthcare provider about which recommended vaccines are right for them.

For those in Vermont, the Vermont Department of Health provides this information about measles, reminding people that measles is preventable when people get vaccinated. They also point out that even though measles was declared eliminated in the United States in the year 2000, outbreaks can still happen in communities with low immunization rates.