The standard schedule: two doses in childhood, then you're protected for life
Most people in the United States need two doses of the measles vaccine, both given in childhood, and then no more doses after that. The first dose goes at 12 to 15 months old. The second dose goes at 4 to 6 years old, before school starts. After those two doses, you have lasting immunity—the vaccine protects you for life in the vast majority of cases.
This two-dose schedule has been standard in the U.S. since the 1980s. It replaced an earlier one-dose approach after researchers found that a small percentage of vaccinated children did not develop immunity from a single shot. The two-dose system solved that problem: studies show that over 99% of people who receive both doses are protected against measles.
If you were vaccinated before 1989, you may have received only one dose. Public health agencies recommend that anyone vaccinated with a single dose get a second dose now, even as an adult, to ensure full protection.
Key Takeaways
- The standard measles vaccine schedule is two doses in childhood: the first at 12 to 15 months and the second at 4 to 6 years old.
- Two doses provide lifelong protection for over 99% of vaccinated people, and no booster doses are needed in adulthood under normal circumstances.
- Anyone who received only one measles vaccine dose before 1989 should get a second dose as an adult to ensure full immunity.
- Healthcare workers, people traveling internationally, and those born in 1957 or later without documented immunity may need to verify their vaccination status or receive additional doses.
- Pregnant people cannot receive the measles vaccine, but immunity from childhood vaccination protects them; unvaccinated pregnant people face serious risks if exposed.
Who needs to check their vaccination record
Not everyone follows the standard two-dose schedule, and some people need to verify what they actually received. If you were born in 1957 or later, you should have documentation of two measles vaccine doses or proof of immunity from a blood test. If you cannot find your vaccination record, your doctor can order a titer—a blood test that measures whether you have antibodies against measles.
Healthcare workers face stricter requirements. Hospitals and clinics typically require proof of two measles vaccine doses or a positive immunity test before hiring. If you work in healthcare and lack documentation, your employer will ask you to get vaccinated or tested.
People who plan to travel internationally should verify their vaccination status before departure. Many countries require proof of measles immunity for entry, and measles outbreaks occur regularly in parts of the world where vaccination rates are lower. If you are unsure whether you were vaccinated, getting a titer test takes about a week and costs between $50 and $200, depending on your insurance and location.
What happens if you were vaccinated only once
A single measles vaccine dose leaves about 5% of people without immunity. That means if you received only one dose and were among that 5%, you could still catch measles if exposed. The problem is you won't know which group you fall into without a blood test.
The CDC recommends that anyone vaccinated with a single dose receive a second dose, regardless of age. There is no upper age limit—adults in their 60s and 70s can safely receive a second dose if they have documentation of only one. The second dose works even if given decades after the first.
If you received one dose as a child and are now an adult, contact your primary care doctor or a local health department clinic. They can review your records and either give you a second dose or order a titer test to check your immunity status.
Pregnancy and measles immunity
Pregnant people cannot receive the measles vaccine because it is a live vaccine—it contains a weakened form of the virus that can pose risks during pregnancy. However, if you were vaccinated as a child, that immunity carries through pregnancy and protects both you and your baby.
If you are pregnant and unsure whether you were vaccinated, a blood test can confirm immunity. If the test shows you are not immune, you cannot be vaccinated during pregnancy, but you can receive the vaccine after delivery, before you leave the hospital. Breastfeeding is safe after measles vaccination.
Unvaccinated pregnant people who are exposed to measles face serious complications, including miscarriage, premature delivery, and low birth weight. If you are planning pregnancy and lack measles immunity, getting vaccinated before conception is important. You should wait at least 28 days after vaccination before trying to conceive.
Booster doses and special circumstances
The standard two-dose childhood schedule provides lifelong protection, and booster doses are not recommended for the general population. However, certain groups may need additional doses or verification of immunity.
People who received the measles vaccine before 1968 may have received an inactivated (killed) vaccine rather than the live vaccine used today. The inactivated vaccine provided weaker and shorter-lasting protection. If you were vaccinated before 1968 and have no record of receiving the live vaccine afterward, the CDC recommends getting two doses of the current live vaccine.
People with certain medical conditions that weaken the immune system—such as HIV, leukemia, or lymphoma—may not develop immunity from vaccination and should not receive the live vaccine at all. If you have an immune system disorder, talk with your doctor about measles protection before traveling or if exposed.
What to do if you cannot find your vaccination record
Vaccination records can be lost, especially if you moved as a child or your family changed healthcare providers. If you need proof of measles immunity and cannot locate your record, you have two options: get revaccinated, or get a blood test.
Revaccination is safe even if you were already vaccinated. Getting two more doses carries no additional risk and guarantees immunity. This is often the simpler choice if you need proof quickly—you can get both doses within a month and then have documentation.
A blood test (titer) tells you whether you are already immune without needing vaccination. This matters if you want to avoid unnecessary shots or if you have a medical reason to avoid vaccination. The test takes about a week for results. If the test shows you are immune, you have proof without additional vaccination. If it shows you are not immune, you can then get vaccinated.
Your primary care doctor, a local health department clinic, or a pharmacy offering vaccines can help you decide which path makes sense for your situation.
Frequently Asked Questions
Do I need a measles booster as an adult?
No. Two doses of measles vaccine in childhood provide lifelong protection for over 99% of people. Booster doses are not recommended for adults unless you received only one dose as a child, in which case you need a second dose to complete the series.
I was vaccinated in the 1970s. Do I need another dose?
If you received two doses of the live measles vaccine in the 1970s, you are protected for life and do not need another dose. If you received only one dose, you should get a second dose now. If you are unsure how many doses you received, a blood test can confirm whether you are immune.
Can I get measles if I was vaccinated?
It is extremely rare. Two doses protect over 99% of vaccinated people. The small percentage who are not protected after two doses can still catch measles if heavily exposed, but this is uncommon. A blood test can tell you whether you are in the protected group.
What if I'm traveling and need proof of vaccination quickly?
You can receive both measles vaccine doses within four weeks—the first dose, then the second dose at least 28 days later. After the second dose, you have immediate protection and can carry proof of vaccination. If you need proof even faster, a blood test showing immunity from past vaccination takes about a week.
Is it safe to get a measles vaccine if I don't know whether I was already vaccinated?
Yes. Revaccination is safe even if you were already immune. Getting vaccinated again causes no harm and guarantees protection. This is often simpler than trying to track down old records or waiting for a blood test result.