The standard measles vaccine schedule starts at 12 months

Children in the United States receive their first measles vaccine (as part of the MMR shot, which covers measles, mumps, and rubella) at 12 months of age. The second dose comes at 4 to 6 years old, before school entry. This two-dose schedule protects roughly 97 percent of people who receive both shots.

The timing matters because infants under 12 months still have some protection from antibodies passed from their mother during pregnancy, but that protection fades. By 12 months, babies are old enough for their immune systems to respond well to the vaccine. Waiting until 4 to 6 years for the second dose gives time to catch anyone who did not respond to the first shot and provides a booster for those who did.

Key Takeaways

  • The first MMR dose is given at 12 months of age, and the second dose at 4 to 6 years old, before school starts.
  • Infants younger than 12 months can receive an early dose if they will travel internationally or are in an outbreak, but this does not count toward the standard two-dose series.
  • Adolescents and adults who were never vaccinated or have no record of vaccination should receive two doses at least 28 days apart.
  • Some people born before 1957 are considered immune because measles was common then, but anyone born in 1957 or later needs documented vaccination or proof of immunity.
  • Your child's pediatrician or local health department can tell you whether your child has received both doses and is fully protected.

Early vaccination for travel or outbreak situations

If your child will travel outside the United States before age 12 months, or if there is a measles outbreak in your area, your pediatrician can give an early dose at 6 to 11 months old. This early dose does not replace the standard schedule—your child still needs the regular first dose at 12 months and the second dose at 4 to 6 years.

The early dose is given because measles spreads quickly in crowded places and in countries where vaccination rates are lower. If your child is exposed to measles before 12 months and has not been vaccinated, the risk of serious illness is highest in infants. Talk to your pediatrician at least 4 to 6 weeks before international travel to decide whether an early dose makes sense for your child.

What happens if your child missed the standard schedule

If your child is older than 12 months and has not yet received any measles vaccine, they can start the series at any time. The two doses must be at least 28 days apart. There is no need to restart the series if the timing was longer than planned—your child's immune system will still respond.

If your child received one dose but missed the second dose at 4 to 6 years old, they can receive it as soon as you schedule it, even if they are now a teenager or young adult. Schools often require proof of two doses before enrollment, so checking your child's vaccination record before the school year starts prevents delays.

Catch-up vaccination for teens and adults

Adolescents and adults born in 1957 or later who have no record of measles vaccination or proof of immunity need two doses of the MMR vaccine, given at least 28 days apart. If you are unsure whether you were vaccinated, your doctor can order a blood test to check for measles immunity. If the test shows you are not immune, vaccination is straightforward and can happen the same day as the test result.

Adults who work in healthcare, education, or childcare, or who plan to travel internationally, should verify their measles immunity. If you received only one dose as a child, one additional dose completes the series. The vaccine is safe for adults and carries the same low risk of side effects as it does for children.

Vaccine side effects and what to expect

Most children have no side effects from the MMR vaccine. Some develop a mild rash 7 to 10 days after the shot, or a low fever. These reactions are normal and fade on their own. Serious side effects are rare—severe allergic reactions occur in fewer than one per million doses.

After vaccination, your child may have soreness at the injection site or mild fussiness. Over-the-counter pain reliever can help if needed. If your child has a severe allergic reaction (difficulty breathing, swelling of the face or throat), seek emergency care immediately, though this is extremely uncommon.

Who should not receive the MMR vaccine

Children with severe allergies to gelatin or the antibiotic neomycin should not receive MMR. Pregnant people should not be vaccinated, though the vaccine is safe to give right after delivery. Children with certain immune system disorders or those taking medications that weaken immunity may need to wait or skip the vaccine—your pediatrician will discuss this based on your child's specific condition.

If your child has had a severe allergic reaction to a previous MMR dose, they should not receive another dose. If your child had a severe allergic reaction to eggs, discuss this with your pediatrician before vaccination, though egg allergy alone is not a reason to avoid MMR.

How to find your child's vaccination record

Your pediatrician's office keeps a copy of your child's vaccination record. You can also request records from the clinic or hospital where your child was vaccinated. Many states have an immunization registry—a database that tracks vaccinations—and you can contact your state health department to see whether your child's doses are recorded there.

Schools require proof of vaccination before enrollment. If you cannot locate your child's original records, your pediatrician can revaccinate your child (there is no harm in receiving extra doses), or your state health department may be able to retrieve records from the registry. Keep a copy of your child's vaccination record at home for your own reference and to bring to appointments.

Frequently Asked Questions

Can my baby get the measles vaccine before 12 months?

Yes, if you are traveling internationally or there is an outbreak, your pediatrician can give a dose at 6 to 11 months old. This early dose does not count as one of the two required doses, so your child still needs the standard first dose at 12 months and the second dose at 4 to 6 years old.

What if I do not know whether my child was vaccinated?

Contact your pediatrician or the clinic where your child received care. If records cannot be found, your child can be revaccinated—there is no risk from receiving extra doses. Your state health department's immunization registry may also have a record.

Is the MMR vaccine safe for children with egg allergies?

Yes. The MMR vaccine is safe for children with egg allergies, even severe ones. The amount of egg protein in the vaccine is extremely small. Tell your pediatrician about the allergy so they can monitor your child for a few minutes after the shot, but egg allergy is not a reason to delay or skip vaccination.

Can adults get the measles vaccine if they were never vaccinated as children?

Yes. Adults born in 1957 or later who have no record of vaccination should receive two doses at least 28 days apart. A blood test can confirm whether you are immune before vaccination. The vaccine is safe and effective for adults of any age.

Do I need a booster dose of the measles vaccine as an adult?

No. Two doses of the MMR vaccine provide lifelong protection for nearly all people. A third dose is not routinely recommended unless you work in healthcare or have a specific exposure risk—your doctor can advise based on your situation.