Measles and Vaccination: What You Need to Know

Updated March 10, 2025

The measles vaccine first became available in this country in 1963, and the current 2-dose childhood regimen became accepted practice in 1989. By 2000, case counts were so low that measles was declared to have been “eliminated” from the US, and medical students and young practitioners quickly became unfamiliar with the disease, many never having seen a case of the virus. However, measles are back, and spreading throughout communities in the US.

The vast majority of measles cases have occurred in unvaccinated individuals.

Measles vaccination rates in the U.S. have declined over the past decade, falling below the critical threshold needed for herd immunity. During the 2023–24 school year, nationwide vaccination coverage among kindergarteners dropped below 93%, with MMR coverage at 92.7%, marking the fourth consecutive year below the Healthy People 2030 target of 95%.

• People who have never had measles and have never been vaccinated
• Babies younger than 1 year, since they are too young to be vaccinated
• People who were born in 1957 or later, and were vaccinated before 1968

In most people, measles is a self-limited, benign albeit unpleasant disorder characterized by a flu-like syndrome (runny nose, cough, and red, light-sensitive eyes), fever, and the classic rash that begins on the head and spreads down the trunk, arms, and legs. Typically, it lasts no longer than 10 days.

Most people with healthy immune systems will recover within 7 to 10 days. However, some people can develop severe complications such as hepatitis (inflammation of the liver), pneumonia, and encephalitis (inflammation of the brain). The risk of dying from measles is 3 out of every 1,000 people who get the disease.

You don’t need to get vaccinated if you meet any of these criteria:

• You have blood tests that show you are immune to measles, or
• You received two full doses of the measles vaccine (usually as a component in the MMR vaccine) as a child, or at least one dose as an adult, or
• You had a previous measles infection (confirmed by laboratory testing), or
• You were born before 1957

The vaccine is highly effective. Between 97 and 99 percent of vaccine recipients develop immunity to measles.

The protective effect can be seen within several days of being vaccinated.

Side effects are uncommon. When they do occur they are mild and may consist of discomfort at the site of injection, a transient rash, low-grade fever, joint aches or swollen lymph nodes. Rarely, a child may develop a febrile seizure (a convulsion caused by fever that is typically harmless). Very uncommonly (in about 1 person out of 25,000 to 40,000), there may be a temporary drop in the platelet count (a type of blood cell that regulates blood clotting). These side effects pale in comparison to the risk of severe complications from the disease.

No. Multiple studies have definitively shown that there is no link between the vaccine and autism.

The measles vaccine is a live vaccine, which means that it contains a weakened form of the virus. Because the measles vaccine is live, it should not be given to pregnant women or anyone whose immune system is compromised either by disease or immunosuppressive medications. You also shouldn’t get the vaccine if you had a life-threatening allergic reaction to previous doses of the vaccine or any of its components.

Adults who don’t have evidence of immunity should get at least one dose of the MMR vaccine.

An inactivated (non-live) measles vaccine was administered to some individuals between 1963 and 1968. This version of the measles vaccine was later found to be ineffective, so adults who received the inactivated vaccine before 1968 should get at least one dose of the MMR vaccine.

Some adults should receive two doses of the vaccine. This includes:

• University students
• Healthcare personnel
• International travelers
• Household contacts and close contacts of people with immunocompromising conditions
• People living with HIV who don’t have severe immunocompromise

There are no recommendations for children over 1 year old or adults to receive a third dose (“booster”) of the measles, mumps, and rubella (MMR) vaccine during measles outbreaks.

If you aren’t certain about your vaccination status, talk to your provider about whether you need a vaccine, or whether you should be tested for antibodies. An antibody test is a lab test that measures the level of antibodies to measles in your blood. Your provider can then determine whether you should be vaccinated.

Millions of people over many years have safely been vaccinated. Make sure you and your family are protected against this latest outbreak.