Children get the measles vaccine starting at 12 months old

The measles vaccine is given as part of the MMR shot, which protects against measles, mumps, and rubella. Your child receives the first dose at 12 to 15 months of age. A second dose follows at 4 to 6 years old, before school starts. This two-dose schedule gives children the strongest protection against measles.

The timing matters because babies under 12 months still have some protection from antibodies passed from their mother during pregnancy, but this protection fades. By 12 months, your child's own immune system can respond well to the vaccine. The second dose at school age catches any children whose immune systems did not respond fully to the first shot.

Key Takeaways

  • The first MMR dose is given at 12 to 15 months of age at a routine well-child visit.
  • The second MMR dose is given at 4 to 6 years old, typically before kindergarten or first grade.
  • Children who missed these doses can receive them later; there is no upper age limit for catching up.
  • Your pediatrician will tell you the exact dates based on your child's birth date and your local school requirements.

Why the vaccine schedule is spaced this way

Doctors space the two doses about 4 to 6 years apart because the first dose does not protect every child. Studies show that roughly 95 out of 100 children develop immunity after the first shot. The second dose catches the 5 children whose bodies did not respond the first time. Two doses together protect more than 99 out of 100 children.

Waiting until 12 months for the first dose is necessary because younger babies' immune systems are still developing. A vaccine given before 12 months may not work as well because the baby's own antibody-making cells are not yet mature enough. The maternal antibodies still circulating in a younger baby can also interfere with how the vaccine works.

What happens if your child is behind on vaccines

If your child missed the routine schedule, they can receive both doses at any age. There is no deadline or upper age limit. A child who is 3 years old can receive the first dose, then the second dose at least 28 days later. A teenager or young adult who was never vaccinated can also receive both doses on this same schedule.

If your child is starting school and has not had any MMR doses, talk to your pediatrician right away. Most schools require proof of at least one MMR dose before entry, though some states allow medical or religious exemptions. Your doctor can give both doses quickly if needed—the second dose can be given as soon as 28 days after the first, rather than waiting years.

Special situations that change the timing

Children traveling internationally before 12 months may receive an early dose of MMR as young as 6 to 11 months, then receive the regular two-dose series starting at 12 months. This early dose does not count toward the two-dose series; it is an extra dose for protection during travel.

Children with weakened immune systems due to HIV, cancer treatment, or certain medications may need a different schedule or may not be able to receive the live MMR vaccine at all. Your child's doctor will discuss alternatives if this applies to your family. Children who received a blood transfusion or certain blood products also need to wait a specific amount of time before receiving MMR, because those products contain antibodies that can interfere with the vaccine.

How to keep track of your child's vaccine record

Your pediatrician's office keeps a record of every vaccine your child receives. You should also keep a copy at home. Many states now use an online system where you can view your child's vaccine record through your doctor's patient portal or through a state immunization registry.

When your child starts school or daycare, you will need to provide proof of vaccination. Bring your child's vaccine record card or ask your doctor's office for an official copy. If you cannot find your child's records, your pediatrician can check the state registry or give the vaccines again if needed—there is no harm in receiving a dose you may have already had.

Frequently Asked Questions

Can my child get the MMR vaccine before 12 months?

Only in special cases, such as international travel. For routine protection, the first dose is given at 12 to 15 months. If your child will be traveling to a country with measles, your doctor may give an early dose at 6 to 11 months, but your child will still need the full two-dose series starting at 12 months.

What if my child is allergic to eggs or gelatin?

Most children with egg allergies can safely receive the MMR vaccine. The amount of egg protein in the vaccine is very small. Tell your pediatrician about any allergies before the visit so they can observe your child for 15 minutes after the shot. A severe gelatin allergy is rare, but mention it to your doctor.

Does my child need the MMR vaccine if they already had measles?

If your child had measles, they have natural immunity and do not need the vaccine. However, natural immunity to mumps and rubella from infection is less reliable. Your doctor can do a blood test to check immunity to all three diseases if you are unsure whether your child had measles.

Can my child get other vaccines at the same time as MMR?

Yes. The MMR vaccine can be given on the same day as other vaccines, either in the same arm or different arms. Your pediatrician will follow the standard immunization schedule, which spaces out vaccines to protect your child against multiple diseases efficiently.

What are the side effects of the MMR vaccine?

Most children have no side effects or only mild ones like arm soreness or low fever. A rash can appear 7 to 10 days after the shot in some children and is not contagious. Serious side effects are very rare. Your pediatrician will discuss what to expect and when to call if you have concerns.