Is it acceptable to receive another Measles, Mumps, and Rubella (MMR) vaccine instead of checking antibody titers when traveling abroad?

MMR Vaccination for International Travel

Receiving another MMR vaccine instead of checking titers is acceptable and recommended for international travel, as documented vaccination supersedes the results of serologic testing according to CDC guidelines. 1

Evidence-Based Approach to MMR Vaccination for Travel

Presumptive Evidence of Immunity

For adults, presumptive evidence of immunity to measles, mumps, and rubella includes any of the following:

• Written documentation of vaccination with appropriate doses of MMR vaccine
• Laboratory evidence of immunity
• Laboratory confirmation of disease
• Birth before 1957 (with some exceptions) 1

Recommendations for International Travelers

For those with documented 2 doses of MMR:

• No additional vaccination or titer checking is needed
• The CDC specifically states that "for HCP who have 2 documented doses of MMR vaccine or other acceptable evidence of immunity to measles, serologic testing for immunity is not recommended" 1
• This guidance applies to international travelers as well

For those with only 1 documented dose:

• A second dose of MMR is recommended for international travelers 1
• The second dose should be administered at least 28 days after the first dose

For those with unknown or no vaccination history:

• Two doses of MMR vaccine are recommended, separated by at least 28 days 1

Rationale for Vaccination Without Checking Titers

1. Cost-effectiveness: Prevaccination antibody screening is not necessary unless considered cost-effective by the medical facility 1

2. Documentation supersedes serology: The ACIP clearly states that "documented age-appropriate vaccination supersedes the results of subsequent serologic testing" 1, 2

3. Safety profile: The MMR vaccine has an excellent safety profile with serious adverse events being extremely rare 2

4. Rapid protection: During outbreaks or when rapid protection is needed (such as before international travel), serologic screening before vaccination is not recommended 1

Safety Considerations

The MMR vaccine has a well-established safety profile with minimal risks:

• Anaphylaxis: approximately 1.0–3.5 occurrences per million doses 1
• Thrombocytopenia: three to four cases per 100,000 doses 1
• Arthralgia/arthritis: primarily affects rubella-susceptible postpubertal females (25% develop arthralgia, 10% develop acute arthritis-like symptoms) 1

Special Situations

Previously Vaccinated with Inactivated Measles Vaccine (1963-1967)

• Should receive two doses of MMR vaccine separated by at least 28 days 1
• This is particularly important when risk of exposure is increased (e.g., during international travel) 1

Previously Vaccinated with Unknown Type of Vaccine (1963-1967)

• Should be revaccinated as they may have received inactivated vaccine 1
• Those who received a vaccine of unknown type after 1967 need not be revaccinated unless the original vaccination occurred before the first birthday 1

Long-term Immunity

Research shows that MMR vaccination provides long-lasting immunity:

• Antibodies against measles and rubella decline moderately after vaccination but remain above seropositivity thresholds for at least 10 years 3
• Anti-mumps antibody levels remain relatively stable over a 10-year follow-up period 3

Common Pitfalls to Avoid

1. Unnecessary titer checking: Checking titers when there is documented evidence of appropriate vaccination is unnecessary and not recommended by the ACIP 1, 2

2. Delaying travel vaccination: Waiting for titer results could delay protection when traveling to high-risk areas

3. Misinterpreting negative titers: Even if titers are negative or equivocal in someone with 2 documented doses of MMR vaccine, the ACIP does not recommend an additional dose 1

4. Confusing primary series with boosters: The second dose of MMR is not considered a booster but completes the primary immunization series 2

By following these evidence-based guidelines, travelers can ensure adequate protection against measles, mumps, and rubella without unnecessary testing or delays.