MMR Vaccination in Adults
All adults born in 1957 or later should receive at least one dose of MMR vaccine unless they have documented evidence of immunity, and specific high-risk groups require a two-dose series administered at least 28 days apart. 1, 2
Evidence of Immunity
Adults are considered immune to measles, mumps, and rubella if they meet any of the following criteria:
- Birth before 1957 (except healthcare personnel—see below) 1
- Documentation of age-appropriate vaccination with MMR 1, 3
- Laboratory evidence of immunity to each disease 1, 3
- Laboratory confirmation of disease (provider diagnosis alone is NOT acceptable evidence for any component) 2, 3
Single-Dose MMR Recommendations
One dose of MMR is recommended for:
- All adults born in 1957 or later without evidence of immunity 1
- Women of childbearing age without evidence of rubella immunity, regardless of birth year 1
- Adults not in high-risk categories who lack documented immunity 1
Two-Dose MMR Requirements
A second dose (administered at least 28 days after the first) is required for: 2
- Healthcare personnel born in 1957 or later (for measles and mumps protection) 1, 2
- Students in postsecondary educational institutions 1, 2
- International travelers 1, 2
- Adults in outbreak settings or recently exposed to measles or mumps 1, 2
- Adults vaccinated with killed measles vaccine or unknown vaccine type between 1963-1967 1, 2
Critical Caveat for Healthcare Personnel
Healthcare workers born before 1957 should NOT be assumed immune—facilities should consider routine vaccination with 2 doses of MMR or document laboratory evidence of immunity. 1, 2 This represents a major departure from the general population guidance and is frequently overlooked in practice.
Dosing Interval
- The minimum interval between MMR doses is 28 days (4 weeks) for adults 2, 4
- The second dose is not a booster but addresses primary vaccine failure in the small proportion who don't respond to the first dose 2
- If inadvertently given before 28 days, the dose must be repeated after the appropriate interval 2
Special Populations
Pregnant Women
- MMR is contraindicated during pregnancy 1, 5
- Women without evidence of rubella immunity should receive MMR immediately upon completion or termination of pregnancy, before discharge from the healthcare facility 1
- Pregnancy should be avoided for 4 weeks after vaccination 5
Immunocompromised Patients
- MMR is contraindicated in severe immunodeficiency 1
- HIV-infected persons without severe immunosuppression may receive MMR 3
Safety Profile
MMR vaccine in adults has an excellent safety profile with serious adverse events occurring at rates ≤6 per 100,000 doses. 6 Common non-serious reactions include:
- Arthropathy (263 per 100,000 doses) 6
- Injection site reactions (157 per 100,000 doses) 6
- Rash (113 per 100,000 doses) 6
- Fever (19% of reports) 7
These reactions typically occur during the risk window post-vaccination and should be anticipated when counseling patients. 6