Vaccines: Measles, Mumps, and Rubella (MMR)

Specific vaccination recommendations vary among countries or even within a given country. Local or country-specific guidelines should be consulted.

1. Vaccines: Combined measles, mumps, and rubella (MMR) vaccines contain live attenuated viruses. A combined measles, mumps, rubella, and varicella (MMRV) vaccine is also available.

2. Indications: MMR or MMRV vaccines form a part of the primary vaccination schedule across North America. Individuals who have not received primary MMR vaccination should be vaccinated; immunization against measles is particularly important in vulnerable populations, such as health-care workers, international travelers, immunocompromised patients, and those in the military. Patients born before 1970 are presumed to have natural immunity to measles and do not require vaccination; exceptions to this include the vulnerable populations outlined above.

A person is considered immune to measles when ≥1 of the following criteria is fulfilled:

1) A well-documented history of measles diagnosed by a physician and confirmed by laboratory tests.

2) Positive serum IgG to measles.

3) Documented vaccination with 2 doses of measles vaccine (either monovalent or MMR) administered at a ≥4-week interval.

3. Contraindications include general contraindications for all vaccines and specific contraindications for live attenuated vaccines. Vaccination is contraindicated in those with a history of a systemic anaphylactic reaction to neomycin. Caution is necessary in patients with a history of significant thrombocytopenia or thrombocytopenic purpura because MMR vaccines may very rarely be associated with thrombocytopenia (<1/10,000 doses); however, it is usually asymptomatic. If a patient requires skin or interferon gamma release assay (IGRA) testing for tuberculosis, this should be done prior to or 4 to 6 weeks after the administration of MMR or MMRV vaccine. The use of salicylates should be avoided in patients receiving the MMRV vaccine for 6 weeks after immunization due to the risk of Reye syndrome. In the case of accidental vaccination of women in early pregnancy, no harmful effects on the fetus have been observed. Therefore, no specific action is needed in such patients and routine pregnancy testing prior to vaccination is not recommended.

4. Immunization schedule: The primary vaccination series includes 2 doses of MMR or MMRV vaccine administered subcutaneously. The first dose should be given between 12 to 15 months old, with the second dose given at 18 months old; the second dose should not be delayed past the age of school entry. MMR vaccination results in seroconversion in 85% to 95% of individuals after a single dose and a nearly 100% seroconversion rate after the second dose.

The accelerated vaccination schedule for previously unimmunized children and adolescents requires 2 doses of MMR vaccine given ≥4 weeks apart. MMRV vaccine may be used in this accelerated schedule if the patient is <13 years old.

For patients born before 1970 engaged in health-care work, international travel, or military activities, administer 2 doses of MMR. In susceptible adults born in or after 1970, administer 1 dose of MMR.

5. Postexposure prophylaxis may use either MMR vaccine or immunoglobulin therapy and should be initiated after close contact of a susceptible individual with:

1) A person with measles: In susceptible immunocompetent patients >6 months of age with no contraindications, start vaccination within 72 hours of exposure. The use of human immunoglobulin should be considered within 6 days of exposure in pregnant women, immunocompromised patients, and infants <6 months old; it should also be considered in immunocompetent infants 6 to 11 months old presenting within 72 hours to 6 days after exposure. In patients receiving polyclonal intravenous immunoglobulin (IVIG) replacement therapy, a dose >100 mg/kg administered within 3 weeks prior to exposure is sufficient to protect against infection. Susceptible pregnant women should be vaccinated after delivery.

2) A person with rubella: In susceptible women in the first or second trimester of pregnancy and with a history of close contact with a person with rubella confirmed by laboratory tests, consider the administration of immunoglobulin at a dose of 0.55 mL/kg (see above; this is controversial and does not eliminate the risk of congenital rubella syndrome). Susceptible pregnant women should be vaccinated as soon as possible after delivery.

6. Adverse events: Transient erythema at the injection site (>10%), fever (<10%). In <10% of vaccine recipients there is a risk of a rash resembling MMR. Encephalitis has been reported (1/1,000,000 vaccine doses). A meta-analysis comprising over 1,200,000 patients showed no evidence of a causal relationship between autism spectrum disorder and MMR vaccination.

When the first dose of MMRV vaccine is administered to children aged 12 to 23 months, there is a higher risk of fever and febrile seizure compared with the administration of separate doses of MMR and univalent varicella at the same clinic visit.