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 recommendation and is frequently overlooked in practice.
Dosing Interval
- Minimum interval between doses: 28 days (4 weeks) 2, 4
- The second dose is not a booster but addresses primary vaccine failure in those who did not 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 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
Common Pitfalls
- Do not accept provider-diagnosed disease as evidence of immunity—laboratory confirmation is required 2, 3
- Do not assume birth before 1957 confers immunity in healthcare workers—this exception is frequently missed 2, 5
- Do not delay vaccination to give separate component vaccines—MMR is the vaccine of choice when susceptibility to multiple components exists 5
- Do not forget to counsel women of childbearing age about congenital rubella syndrome risk 1, 5
Safety Profile
MMR in adults is well-tolerated with rare serious adverse events (≤6 per 100,000 doses). 6 Common non-serious reactions include arthropathy (263 per 100,000), injection site reactions (157 per 100,000), and rash (113 per 100,000). 6 Females account for 77% of adverse event reports, with fever, rash, pain, and arthralgia being most common. 7