MMR Vaccine in Adults
Adults born in 1957 or later should receive at least one dose of MMR vaccine, with two doses recommended for healthcare workers, students in postsecondary institutions, and international travelers, administered at least 28 days apart. 1, 2
Dosing and Schedule
Standard Dosing:
- Single dose: 0.5 mL administered subcutaneously or intramuscularly 3
- Minimum interval between doses: 28 days (4 weeks) 1, 2, 3
One-Dose Recommendations:
- General adult population born in 1957 or later without evidence of immunity 1, 2
- Women of childbearing age for rubella protection (regardless of birth year) 1, 2
Two-Dose Recommendations: The following groups require two doses administered at least 28 days apart 1, 2, 4:
- Healthcare personnel
- Students in postsecondary educational institutions
- International travelers
- Adults in outbreak settings
- Those previously vaccinated with killed measles vaccine (1963-1967)
- Those vaccinated with unknown vaccine type (1963-1967)
Evidence of Immunity (No Vaccination Needed)
Adults are considered immune with any of the following 1, 2, 5:
- Documentation of two appropriately spaced MMR doses
- Laboratory evidence of immunity to all three diseases
- Laboratory confirmation of disease
- Birth before 1957 (with important exceptions below)
Critical Caveat: Birth before 1957 is NOT considered evidence of immunity for healthcare personnel—these individuals should still be vaccinated if they lack laboratory evidence of immunity or documentation of vaccination 1, 2, 1.
Contraindications
Absolute contraindications 3:
- Pregnancy (MMR is a live virus vaccine)
- Severe immunodeficiency (HIV with severe immunosuppression, immunosuppressive therapy, primary immunodeficiency)
- History of anaphylactic reaction to vaccine components
Important for Practice: If a woman is found to be pregnant after receiving MMR, no intervention is needed, but complete the series after pregnancy 6, 2. Women without evidence of rubella immunity should receive MMR immediately postpartum before hospital discharge 1, 2.
Special Populations
Healthcare Workers: This is a high-priority group. Unvaccinated healthcare personnel born before 1957 without laboratory evidence of immunity should receive two doses of MMR 1, 2, 1. During mumps outbreaks, strongly consider a second dose even for those born before 1957 1.
Post-Exposure Prophylaxis: Administer MMR within 72 hours of measles exposure for unvaccinated individuals without contraindications 3. This provides some protection and is preferred over waiting.
HIV-Infected Persons: MMR can be given to HIV-infected adults aged ≥12 months who do NOT have evidence of current severe immunosuppression 5. This represents an important expansion of vaccination eligibility.
Administration Details
- Reconstitute immediately before use with supplied diluent only 3
- Use within 8 hours if stored at 2-8°C after reconstitution 3
- Administer 0.5 mL subcutaneously or intramuscularly 3
- Do not use if particulates present or discolored 3
Common Pitfalls to Avoid
- Don't assume birth before 1957 equals immunity in healthcare workers—this is the most common error in practice
- Don't delay vaccination in women of childbearing age who lack immunity—vaccinate immediately postpartum
- Don't withhold MMR from adults who "think" they had measles/mumps—provider-diagnosed disease documentation is no longer acceptable evidence of immunity for measles and mumps 5
- Don't forget the 28-day minimum interval when giving two doses
- Don't give MMR to pregnant women, but if inadvertently given, reassure the patient—no intervention needed 6, 2
Safety Profile
MMR in adults is safe and well-tolerated. In a review of 3,175 adult reports to VAERS over 10 years, only 5% were serious, with the most common symptoms being fever (19%), rash (17%), and pain (13%) 7. A third dose study showed mild, transient symptoms in 18% of recipients, with median duration of 1-2 days 8.