What is the recommended rubella vaccine dose, route, and timing for children (first dose at 12–15 months, second at 4–6 years), adolescents or adults, and post‑exposure?

Rubella Vaccine Dosage and Administration

Administer rubella vaccine (as MMR) at 0.5 mL subcutaneously or intramuscularly: first dose at 12–15 months, second dose at 4–6 years, with a minimum 4-week interval between doses for children, and two doses 4 weeks apart for unvaccinated adolescents and adults born in 1957 or later. 1, 2, 3

Standard Pediatric Schedule

First Dose (12–15 Months)

• The first dose should be administered at 12–15 months of age as 0.5 mL of reconstituted MMR vaccine given subcutaneously or intramuscularly. 4, 1, 3
• The minimum age for valid MMR vaccination is 12 months; doses given before the first birthday do not count toward the routine series and must be repeated. 1
• Seroconversion rates are approximately 93% at 12 months versus 98% at 15 months, but this difference has limited clinical relevance because the second dose ensures near-universal immunity. 1

Second Dose (4–6 Years)

• The second dose is routinely recommended at 4–6 years of age (before kindergarten or first grade entry), using the same 0.5 mL dose. 4, 1, 3
• The minimum interval between doses is 4 weeks, so the second dose may be administered earlier than 4–6 years if needed, provided at least 28 days have elapsed since the first dose. 4, 1, 3
• After two properly timed doses, children are considered fully immunized; routine serologic testing is not recommended. 1

Catch-Up Vaccination

Children and Adolescents

• Children who missed the routine schedule should receive two doses separated by at least 4 weeks, regardless of current age or elapsed time. 1, 2
• Never restart the vaccine series due to timing delays—simply continue with the minimum 4-week interval between doses. 1
• For a child who received only one dose years earlier (e.g., at age 2, now age 7), administer the second dose immediately without additional waiting. 1

Adults

• Adults born in 1957 or later without documentation of vaccination or laboratory evidence of immunity should receive at least one dose of MMR. 2, 5
• High-risk adults (healthcare personnel, international travelers, students in postsecondary institutions, household contacts of immunocompromised persons) require a complete two-dose series with at least 4 weeks between doses. 2
• Adults born before 1957 are generally considered immune, except healthcare personnel who should still be vaccinated regardless of birth year. 2

Post-Exposure Prophylaxis

• For measles post-exposure prophylaxis, administer a dose of MMR within 72 hours after exposure. 3
• This recommendation applies specifically to measles exposure; rubella post-exposure vaccination is less time-sensitive but should still be given promptly to susceptible individuals. 3

Special Populations and Circumstances

Infants in High-Risk Settings

• During measles outbreaks or international travel, infants aged 6–11 months may receive a single dose of MMR for protection, but this dose does not count toward the routine two-dose schedule. 2
• These infants must be revaccinated at 12–15 months and again at 4–6 years because maternal antibodies may interfere with seroconversion. 2

Women of Childbearing Age

• All women of childbearing age should be considered susceptible unless they have documentation of at least one MMR dose or serologic evidence of immunity. 2
• MMR should be offered to all non-immune women of childbearing age; vaccination can be given immediately postpartum if the woman is pregnant. 2

Administration Technique and Vaccine Handling

Reconstitution and Injection

• Use only the supplied sterile diluent (preservative-free) to reconstitute the lyophilized vaccine; withdraw the entire 0.5 mL volume and inject slowly into the vaccine vial. 3
• Gently agitate to dissolve completely; the reconstituted vaccine should appear as a clear yellow liquid without particulates. 3
• Administer immediately after reconstitution; if not used immediately, store at 2–8°C protected from light for up to 8 hours, then discard. 3

Route of Administration

• MMR may be given subcutaneously or intramuscularly; both routes are equally immunogenic and well-tolerated. 3, 6
• Intramuscular administration results in fewer injection-site reactions (erythema, swelling) compared to subcutaneous administration, though both are acceptable. 6

Vaccine Formulation Considerations

MMR vs. MMRV

• For children aged 12–47 months receiving the first dose, use separate MMR and varicella vaccines rather than MMRV due to increased febrile seizure risk (approximately one additional seizure per 2,300–2,600 doses). 1, 5
• For the second dose at any age or first dose at ≥48 months, MMRV is preferred over separate injections because the febrile seizure risk does not apply after age 4 years. 1, 5
• Children with a personal or family history of seizures should receive separate MMR and varicella vaccines instead of MMRV at any age. 1, 2

Vaccine Interchangeability

• All MMR vaccines (e.g., M-M-R II, PRIORIX) are fully interchangeable for all indications; any brand may be used to complete the series. 5

Contraindications and Precautions

Absolute Contraindications

• Severe immunocompromise (e.g., severe HIV infection, high-dose systemic corticosteroids, chemotherapy) is an absolute contraindication. 2, 5
• Pregnancy is a contraindication; however, inadvertent vaccination during pregnancy is not an indication for termination. 2
• Severe anaphylactic reaction to vaccine components (neomycin, gelatin) contraindicates further doses. 5

Timing with Other Vaccines

• MMR may be administered simultaneously with other vaccines at different anatomic sites. 2
• If not given simultaneously with other live vaccines, separate MMR from another live vaccine by at least 28 days. 2

Clinical Efficacy and Duration of Immunity

• Greater than 95% of susceptible persons develop antibody after a single dose, with clinical efficacy exceeding 90% for at least 15 years. 2
• Approximately 5% of children experience primary vaccine failure after the first dose; the second dose corrects this immunity gap, achieving near-universal protection. 1
• Vaccine-induced immunity is considered long-term, probably lifelong. 2

Common Pitfalls to Avoid

• Do not delay catch-up vaccination waiting for the "ideal" age—start immediately with the minimum 4-week interval. 1
• Do not restart the vaccine series if there has been a long gap between doses; simply continue where you left off. 1
• Do not use MMRV reflexively for first doses in children 12–47 months due to increased febrile seizure risk. 1
• Do not perform routine serologic testing in healthy children after two documented doses; documentation of vaccination is sufficient evidence of immunity. 1