What are the immediate recommendations for a patient without a Measles, Mumps, and Rubella (MMR) record on file who has been exposed to measles?

Management of Measles Exposure in Patients Without MMR Record

For patients without MMR vaccination records who have been exposed to measles, immediate administration of MMR vaccine within 72 hours of exposure is recommended as first-line post-exposure prophylaxis, while immune globulin should be administered within 6 days of exposure for those with contraindications to vaccination or when more than 72 hours have elapsed since exposure. 1

Immediate Post-Exposure Management Algorithm

Step 1: Assess timing since exposure

• Within 72 hours of exposure:

  • Administer MMR vaccine to immunocompetent individuals ≥12 months of age without evidence of immunity 1
  • This may prevent or modify disease if given within this timeframe

• Between 72 hours and 6 days of exposure:

  • Administer immune globulin (IG) as the preferred intervention 1

Step 2: Evaluate patient risk factors and contraindications

For standard risk patients (immunocompetent):

• Age ≥12 months without evidence of immunity: MMR vaccine within 72 hours 1
• If >72 hours but <6 days since exposure: IG 0.25 mL/kg (maximum 15 mL) 1

For high-risk patients:

• Pregnant women without evidence of immunity:

  • IG 0.25 mL/kg (maximum 15 mL) within 6 days of exposure 1, 2
  • MMR vaccine is contraindicated during pregnancy 1

• Infants <6 months of age:

  • IG 0.25 mL/kg within 6 days of exposure 1, 2
  • Note: Infants <6 months typically have some maternal antibody protection 1

• Infants 6-12 months of age:

  • MMR vaccine within 72 hours if possible 1
  • If >72 hours but <6 days: IG 0.25 mL/kg 1, 3
  • Note: Will still need routine MMR doses after 12 months of age 1

• Immunocompromised persons:

  • IG 0.5 mL/kg (maximum 15 mL) regardless of vaccination status 1
  • For severely immunocompromised: Consider IGIV 400 mg/kg as alternative 2, 3

Important Considerations

1. Effectiveness of post-exposure prophylaxis:

   • MMR vaccine effectiveness as PEP: 83.4% 4
   • IG effectiveness as PEP: up to 100% in preventing clinical disease 4
   • Combined effectiveness (any PEP): 92.9% 4

2. Timing is critical:

   • The 72-hour window for vaccine and 6-day window for IG are evidence-based cutoffs 1, 5
   • Earlier administration within these windows likely provides better protection 5

3. For patients receiving IGIV therapy:

   • If exposed within 3 weeks of receiving standard IGIV dose (100-400 mg/kg), additional IG is not needed 1
   • If exposed >3 weeks after IGIV, consider additional dose 1

4. Documentation and follow-up:

   • Document administration of post-exposure prophylaxis
   • For those receiving IG, observe for signs of measles for 28 days (IG may prolong incubation period) 1
   • For infants or others receiving MMR before routine schedule, ensure they still receive routine MMR doses at appropriate intervals 1

Pitfalls to Avoid

1. Delaying intervention: Post-exposure prophylaxis effectiveness depends on prompt administration - act immediately upon learning of exposure 1, 4

2. Misinterpreting immunity status: Absence of vaccination records does not necessarily mean lack of immunity - consider serologic testing if time permits, but don't delay PEP while awaiting results 1

3. Inadequate dosing: Recent studies show declining antibody levels in IG products, requiring careful attention to proper dosing 2, 3

4. Overlooking contraindications: MMR is contraindicated in pregnancy, severe immunosuppression, and those with severe allergic reactions to previous doses 6

5. Failing to consider IGIV for large patients: For individuals ≥30 kg where injection volume is a concern, IGIV (400 mg/kg) may be more appropriate than multiple IM injections 3

The evidence strongly supports immediate intervention following measles exposure, with the specific approach determined by timing since exposure, age, immune status, and presence of contraindications to vaccination.