Two MMR Doses Are About 97% Effective, Ask Before You Travel
The U.S. Centers for Disease Control and Prevention (CDC) says two doses of the measles, mumps, and rubella (MMR) vaccine are about 97% effective at preventing measles, and one dose is about 93% effective; CDC also says to talk to your healthcare provider about the MMR vaccine to prevent measles, especially if you are planning to travel. CDC recommends that anyone traveling internationally be fully vaccinated before travel; infants 6 to 11 months old should get 1 dose before travel, then 2 more doses after their first birthday.
CDC says measles is highly contagious: if one person has it, up to 9 out of 10 people who come into close contact with that person will become infected if they are not protected, and you can get measles in a room where a person with measles has been, even up to 2 hours after that person has left. This article follows CDC's measles overview and measles vaccination pages: symptoms, who is advised to get how many doses, what to do before travel, and what to do if you don't know whether you were vaccinated. Everyone's health is different; if you have questions, ask your health care provider.
What measles is
CDC explains (CDC, About Measles):
- Symptoms: They appear 7 to 14 days after contact with the virus; common symptoms include high fever (may spike to more than 104°F), cough, runny nose, red and watery eyes, and rash.
- Complications: Especially in children younger than 5; common complications are ear infections and diarrhea, and serious ones include pneumonia, encephalitis, and in some cases death.
- How it spreads: Through the air when an infected person coughs or sneezes; you can get measles just by being in a room where a person with measles has been.
- Higher risk of severe illness: Children younger than 5, adults older than 20, pregnant women, and people with weakened immune systems (such as from leukemia or HIV infection).
- In the United States: Measles was declared eliminated in 2000, but since early 2025 cases have been increasing, with several large outbreaks of more than 50 cases; every year, unvaccinated travelers get measles in other countries and bring it back to the United States.
Who is advised to get how many doses
CDC explains (CDC, Measles Vaccination):
- Children: 2 doses are recommended, the first at 12 to 15 months and the second at 4 to 6 years.
- Adults: At least 1 documented dose of MMR is recommended; some higher-risk adults are recommended to have 2 doses if they don't have other evidence of immunity, at least 28 days apart.
- Adults advised to get 2 doses: Students at post-high school institutions, healthcare personnel, international travelers, household or other close contacts of people who are immunocompromised, adults living with HIV who are not severely immunocompromised, and groups at increased risk because of an outbreak.
- During an outbreak: An additional dose may be needed if you have only 1 documented dose; public health authorities will notify people who are at increased risk and should be vaccinated.
Before you travel
- Fully vaccinated first: Anyone traveling internationally is advised to be fully vaccinated before traveling.
- Infants: Infants 6 to 11 months old are advised to get 1 dose before travel, then 2 more doses after their first birthday.
- Not sure if you were vaccinated: First try to find your records; if you don't have written documentation of MMR or other evidence of immunity, you are advised to get vaccinated, especially if traveling internationally; there is no harm in another dose even if you may already be immune.
- Evidence of immunity: At least one of these: written documentation of vaccination, a lab test showing immunity, lab confirmation of having had measles, or birth before 1957.
For other vaccines to get before visiting Taiwan, see Visiting Taiwan? See a Doctor a Month Out; Hep A, B Advised; for where to find adult vaccination records, see No National Vaccine Record Database, Ask Your State Registry.
After exposure to measles
- Within 72 hours: If you don't have immunity and are exposed, talk with your doctor about getting MMR; getting it within 72 hours of the first exposure may give some protection or a milder illness.
- People at high risk of severe disease: They may be given a medicine called immune globulin (IG) within 6 days of exposure.
Check with your provider first if
- Allergies: You had an allergic reaction after a previous dose of MMR or MMRV, or have any severe, life-threatening allergies.
- Pregnancy: If you are or may be pregnant, wait until you are no longer pregnant; avoid getting pregnant for at least 1 month after getting MMR.
- Other: A weakened immune system, bruising or bleeding easily, a recent blood transfusion, tuberculosis, other vaccines in the past 4 weeks, or feeling unwell.
Safety, cost and where to get it
- Safety: CDC says the MMR vaccine is very safe, side effects are usually mild and go away on their own, there is no link between the MMR vaccine and autism, and it is safe for breastfeeding women.
- Can you still get measles?: Some vaccinated people may still get sick if exposed, but symptoms are generally milder and they are less likely to spread it.
- Where to get it: Your or your child's doctor's office is usually the best place; pharmacies, community health clinics and health departments may also have it.
- Cost: Most health insurance plans cover MMR vaccines, and you may want to check with your insurer first; children may be able to get no-cost vaccines through the VFC program.
- School requirements: Childcare and school vaccination requirements are set by state law; there is no federal law requiring them.
For vaccines when your child has no insurance, see Uninsured or on Medicaid, Kids 18 and Under Can Use VFC.
What this article did not check
- State school requirements: CDC says they are set by state law; this article did not check each state's rules.
- MMRV vaccine: Children may get the MMRV vaccine, which also covers chickenpox; this article does not cover the details.
- Current outbreak locations: These two pages do not list them, so this article does not cover them.
FAQ
I don't remember if I got MMR as a child. What should I do?
CDC says to first look for your vaccination records; if you don't have written documentation or other evidence of immunity, you are advised to get vaccinated, especially if traveling internationally; there is no harm in another dose.
Should my baby under 1 get vaccinated before we travel abroad?
CDC recommends that infants 6 to 11 months old get 1 dose of MMR before travel, then 2 more doses after their first birthday.
What if I was exposed to someone with measles?
CDC says people without immunity can talk with their doctor about getting MMR; getting it within 72 hours of the first exposure may give some protection or a milder illness.
Can I still get measles if I'm vaccinated?
CDC says some vaccinated people may still get sick, but symptoms are generally milder and they are less likely to spread it.
Sources and date checked
All checked on 2026-11-02.
- CDC, About Measles (page dated 2026-04-29):https://www.cdc.gov/measles/about/index.html
- CDC, Measles Vaccination (page dated 2026-04-29):https://www.cdc.gov/measles/vaccines/index.html