What are the recommended doses and schedules for Measles, Mumps, and Rubella (MMR) and Varicella vaccines?

MMR and Varicella Vaccination Dosing Schedule

All children should receive two doses of MMR vaccine (first dose at 12-15 months, second dose at 4-6 years) and two doses of varicella vaccine (first dose at 12-15 months, second dose at 4-6 years), with a minimum interval of 4 weeks between MMR doses and 3 months between varicella doses for children under 13 years. 1, 2, 3

MMR Vaccine Dosing

Standard Pediatric Schedule

• First dose: Administer at 12-15 months of age as part of routine childhood immunization 1, 3
• Second dose: Administer at 4-6 years of age (before school entry) 1, 3
• Minimum interval: 4 weeks between doses, though the second dose may be given earlier than 4-6 years if this interval is met 1, 3
• Dose and route: 0.5 mL administered subcutaneously 1

Catch-Up Vaccination

• Children and adolescents who missed the routine schedule should receive two doses separated by at least 4 weeks 1, 3
• Adults born in 1957 or later without documentation of vaccination or immunity should receive at least one dose 1, 4

High-Risk Adults Requiring Two Doses

The following groups need a complete 2-dose series with at least 4 weeks between doses 1, 4:

• Healthcare personnel born in 1957 or later
• Students in postsecondary educational institutions
• International travelers
• Household contacts of immunocompromised persons

Special Circumstances

• Measles outbreak: Infants 6-11 months should receive one dose, but this does not count toward the routine two-dose series 1
• International travel: Infants 6-11 months should receive one dose before travel; the routine series should still begin at 12 months 1, 4
• Postexposure prophylaxis: Administer one dose within 72 hours of measles exposure in unvaccinated persons, then complete the 2-dose series ≥28 days later 1
• Mumps outbreak: A third dose may be recommended for persons at increased risk during outbreaks 1

Varicella Vaccine Dosing

Standard Pediatric Schedule

• First dose: Administer at 12-15 months of age 2, 3
• Second dose: Administer at 4-6 years of age (before school entry) 2, 3
• Minimum interval for children 12 months-12 years: 3 months between doses 2, 3
• Acceptable minimum: If the second dose is inadvertently given 28 days to 3 months after the first dose, it does not need to be repeated 2
• Dose and route: 0.5 mL administered subcutaneously 2

Adolescents and Adults (≥13 Years)

• Two doses required: 0.5 mL each, separated by a minimum of 4 weeks (28 days) 2
• Must use single-antigen vaccine (Varivax): MMRV is not licensed for this age group 2

Priority Groups for Vaccination

Adults at increased risk who lack evidence of immunity should receive two doses 2:

• Healthcare personnel
• Household contacts of immunocompromised persons
• Teachers and daycare employees
• College students and military personnel
• Nonpregnant women of childbearing age
• International travelers

Postexposure Prophylaxis

• Administer vaccine within 3 days of exposure for >90% effectiveness in preventing varicella 2
• Vaccination within 5 days is approximately 70% effective in preventing disease and 100% effective in modifying severe disease 2

MMRV Combination Vaccine Considerations

Age-Specific Recommendations

For first dose in children 12-47 months: Use separate MMR and varicella vaccines rather than MMRV due to increased febrile seizure risk 3

• MMRV carries approximately one additional febrile seizure per 2,300-2,600 doses compared to separate vaccines in children 12-23 months 3

For second dose at any age (15 months-12 years): MMRV is generally preferred over separate injections 3

• No increased risk of febrile seizures with MMRV at second dose compared to MMR + varicella 5

For children ≥48 months (first dose): MMRV is preferred, as 97% of febrile seizures occur in children ≤47 months 3

Contraindication to MMRV

• Personal or family history (sibling or parent) of seizures of any etiology: Use separate MMR and varicella vaccines instead 3, 4

Key Clinical Efficacy Points

MMR Vaccine

• Two doses provide optimal protection: almost all persons who fail to respond to the first dose will respond to the second 1
• The second dose is not a booster but addresses primary vaccine failures 1
• One dose is approximately 95% efficacious for mumps, but field studies show 75-95% effectiveness 1

Varicella Vaccine

• Two-dose efficacy: 98% against any varicella disease and 100% against severe disease 2
• One-dose efficacy: 94% against any disease 2
• Recipients of two doses are 3.3-fold less likely to experience breakthrough varicella 2
• After two doses, >99% of children achieve protective antibody levels compared to 76-85% after one dose 2

Critical Contraindications

Both MMR and Varicella Vaccines

• Severe immunocompromise (HIV with CD4 <15%, hematologic/solid tumors, congenital immunodeficiency) 2, 3
• High-dose systemic corticosteroids (≥2 mg/kg/day prednisone or ≥20 mg/day for ≥14 days): wait at least 1 month after discontinuation before vaccinating 2
• Pregnancy: vaccinate immediately postpartum if non-immune 1, 2, 4
• Severe anaphylactic reaction to vaccine components (neomycin or gelatin for varicella) 2

Important Exception

• Egg allergy is NOT a contraindication for varicella vaccine, as it contains no egg protein 2

Storage and Handling

• Store lyophilized vaccines at 2-8°C (35.6-46.4°F) or colder 1
• Protect from light, which may inactivate vaccine viruses 1
• Reconstituted vaccine must be used within 8 hours and stored at 2-8°C 1
• Do not freeze reconstituted vaccine 1

Interchangeability

• MMR vaccines: PRIORIX and M-M-R II are fully interchangeable for all indications 1
• Varicella vaccines: Monovalent varicella vaccine (Varivax) and MMRV (ProQuad) contain the same varicella antigen and are interchangeable when age-appropriate 2