Do adult or elderly patients, particularly those who are immunocompromised or have uncertain Measles, Mumps, and Rubella (MMR) vaccination histories, need a measles booster during outbreaks?

MMR Vaccination During Measles Outbreaks in Adults and Elderly

During measles outbreaks, all adults and elderly patients at risk who lack documented evidence of two doses of MMR vaccine should receive vaccination, regardless of age or birth year, with particular urgency for healthcare workers and those in congregate settings. 1

Defining Evidence of Immunity

Adults are considered immune to measles if they have:

• Documentation of two doses of live measles vaccine (preferably MMR) given at least 28 days apart after their first birthday 1, 2, 3
• Laboratory evidence of immunity to measles 1, 2
• Laboratory confirmation of measles disease (note: physician diagnosis alone is NOT acceptable evidence) 4

Critical caveat: Birth before 1957 is generally considered evidence of immunity, but this assumption should NOT be applied to healthcare personnel during outbreaks, as 3.7% of measles cases from 1985-1990 occurred in persons born before 1957 1

Outbreak-Specific Vaccination Strategy

For Adults Born 1957 or Later

All persons at risk during outbreaks who cannot provide evidence of two doses of measles vaccine or other evidence of immunity should receive one dose immediately, followed by a second dose at least 28 days later. 1, 2, 3

For Adults Born Before 1957

Healthcare workers and others with occupational exposure to measles should be vaccinated during outbreaks, even if born before 1957, as birth year alone does not guarantee immunity in these high-risk settings. 1

Healthcare facilities should consider routinely vaccinating unvaccinated personnel born before 1957 who lack laboratory evidence of immunity with 2 doses of MMR vaccine 3

High-Risk Populations Requiring Immediate Attention

The following groups warrant priority vaccination during outbreaks:

• Healthcare personnel in any facility where measles transmission may occur 1
• College and university students in congregate settings where outbreaks commonly sustain transmission 1
• Persons with uncertain vaccination histories, including those who received killed measles vaccine (1963-1967) or vaccine of unknown type, who should receive two doses at least 28 days apart 1

Post-Exposure Prophylaxis Algorithm

For adults exposed to measles without adequate immunity:

Within 72 hours of exposure: Administer MMR vaccine, which is most likely to be protective during this window 1

Within 6 days of exposure (if MMR contraindicated): Administer immune globulin (IG):

• Standard dose: 0.25 mL/kg IM (maximum 15 mL) for immunocompetent persons 1
• If IG is given, live measles vaccine must be delayed 3 months to allow passive antibodies to clear 1
• Intravenous immune globulin (IGIV) is recommended for severely immunocompromised persons and pregnant women 4

Healthcare personnel exposure management: Remove from patient contact for 5-21 days after exposure, as post-exposure prophylaxis is not completely effective 1

Special Populations and Contraindications

Immunocompromised Patients

MMR vaccine is contraindicated in severe immunodeficiency. 2 For immunosuppressed cancer and hematopoietic cell transplant recipients, live attenuated vaccines like MMR cannot be administered, making community exposures potentially life-threatening with no approved antiviral therapies available 5

Pregnant Women

MMR is absolutely contraindicated during pregnancy. 2 Women without evidence of immunity who are exposed should receive IGIV within 6 days 4. Women of childbearing age without rubella immunity should receive MMR immediately after pregnancy completion, before hospital discharge, and avoid pregnancy for 4 weeks post-vaccination 2, 3

Elderly Patients

While the guidelines focus primarily on younger adults, elderly patients in outbreak settings should be evaluated individually. Those in healthcare facilities or congregate living situations with uncertain vaccination histories should be considered for vaccination, as waning immunity from childhood infection may occur 6

Practical Implementation Pitfalls

Common error: Assuming all persons born before 1957 are immune—this is incorrect for healthcare workers during outbreaks 1, 3

Dosing interval mistake: If the second dose is inadvertently given before 28 days, it must be repeated after the appropriate interval 2, 3

Documentation confusion: Physician-diagnosed measles is acceptable evidence for measles immunity but NOT for rubella; laboratory confirmation is required for all three diseases to be considered definitive 4

Vaccine type history: An estimated 600,000-900,000 persons received killed measles vaccine (1963-1967) and should be considered unvaccinated, requiring two doses of live vaccine 1

Safety Profile of Additional Doses

For adults who may have already received two doses but lack documentation, a third dose of MMR is safe and tolerable. In a study of 662 young adults receiving a third dose, only 18% reported mild, transient symptoms (primarily headache, joint problems, diarrhea, lymphadenopathy) with median duration of 1-2 days and minimal healthcare utilization 7