What is the recommended treatment for individuals exposed to measles?

Post-Exposure Prophylaxis for Measles

For immunocompetent individuals ≥12 months exposed to measles, administer MMR vaccine within 72 hours of exposure; if beyond 72 hours but within 6 days, use immune globulin (IG) at 0.25 mL/kg (maximum 15 mL) for high-risk groups only. 1

Immediate Management Based on Timing and Patient Characteristics

Within 72 Hours of Exposure

For most immunocompetent persons ≥12 months:

• Administer MMR vaccine as soon as possible within 72 hours of initial exposure 1
• MMR vaccination is preferable to immune globulin for most settings (daycare, schools, colleges, healthcare facilities) 1
• Vaccine may provide some protection if given promptly, though measles is often not recognized until >72 hours after onset 1

For infants 6-11 months (household contacts):

• MMR vaccine within 72 hours is acceptable 1
• These infants must be revaccinated with two doses starting at 12-15 months, separated by ≥28 days 1

For infants <6 months:

• Administer intramuscular immune globulin (IMIg) at 0.5 mL/kg (maximum 15 mL) if injection volume is not a concern 2, 3
• These infants are usually immune from maternal antibodies but may require prophylaxis if susceptible 1

Beyond 72 Hours but Within 6 Days of Exposure

For susceptible household contacts at high risk:

• Administer IG at 0.25 mL/kg (maximum 15 mL) for immunocompetent persons 1, 4
• High-risk groups include infants ≤12 months, pregnant women, and immunocompromised persons 1, 4
• IG can prevent or modify measles if given within 6 days of exposure 1

For immunocompetent individuals >12 months:

• Current evidence does not support routine IG prophylaxis due to low risk of complications and practical challenges 2
• Focus on high-risk household contacts rather than all exposed individuals 1, 4

Special Populations Requiring Modified Approach

Severely Immunocompromised Patients

These patients require IG prophylaxis regardless of vaccination status:

• Administer IG at 0.5 mL/kg (maximum 15 mL) intramuscularly 1
• This includes severely immunocompromised HIV-infected patients and other symptomatic HIV-infected patients 1
• Alternatively, use intravenous immune globulin (IVIg) at 400 mg/kg if injection volume is a concern or for patients ≥30 kg 2, 5, 3
• MMR vaccine is contraindicated for postexposure prophylaxis in immunocompromised persons 1

For patients already receiving IVIg therapy:

• Standard dose of 100-400 mg/kg should be sufficient if administered within 3 weeks before exposure 1
• If exposed >3 weeks after last IVIg dose, consider an additional dose 1

Pregnant Women

Pregnant women without evidence of measles immunity:

• MMR vaccine is contraindicated during pregnancy 1
• Administer IG at 0.25 mL/kg (maximum 15 mL) if immunocompetent 1, 4
• Consider IVIg at 400 mg/kg for pregnant women ≥30 kg or if injection volume is a concern 2, 5, 3

Critical Follow-Up After IG Administration

Any person who receives IG must subsequently receive MMR vaccine:

• Delay MMR vaccination for 5-6 months after IG administration 4, 6
• This delay is necessary because passively acquired antibodies from IG interfere with vaccine immune response 4, 6
• Failure to provide delayed MMR vaccination leaves the patient vulnerable to future exposures 4

Common Pitfalls to Avoid

Dosing errors:

• Do not use 0.25 mL/kg for immunocompromised patients—they require 0.5 mL/kg 1, 4
• Do not exceed maximum dose of 15 mL for intramuscular IG 1

Timing mistakes:

• Do not assume IG is effective beyond 6 days post-exposure 1
• Do not give MMR vaccine too soon after IG administration—wait 5-6 months 4, 6

Population-specific errors:

• Do not give MMR vaccine to severely immunocompromised patients or pregnant women for postexposure prophylaxis 1
• Do not forget to revaccinate infants who received MMR before 12 months of age 1

Product confusion:

• Do not confuse measles (rubeola) with rubella (German measles)—IG does not prevent rubella or mumps after exposure 1, 4

Evidence Quality Considerations

The recommendations are based primarily on ACIP guidelines from 1998 1 and updated in 2013 3, with recent systematic review data from 2025 showing IG effectiveness ranging from 76-100% and MMR effectiveness from 83.4-100% 7, 8. A 2017 NYC outbreak study demonstrated MMR PEP effectiveness of 83.4% (95% CI 34.4-95.8%) and IG effectiveness of 100% (95% CI 56.2-99.8%) 8. However, declining measles antibody concentrations in donor-derived blood products over time have prompted international guideline revisions recommending higher IG doses or IVIg use 2, 5.