Who is eligible to receive the varicella vaccine?

Varicella Vaccine Eligibility

Varicella vaccine should be given to all immunocompetent individuals aged 12 months and older without evidence of immunity, while certain categories of immunocompromised patients may also receive the vaccine under specific conditions. 1, 2

Eligible Populations

Immunocompetent Persons

• Children aged 12 months-12 years:

  • First dose at 12-15 months of age
  • Second dose at 4-6 years of age (minimum interval of 3 months between doses) 1, 2
  • If second dose administered >28 days after first dose, it's considered valid 1

• Persons aged ≥13 years without evidence of immunity:

  • Two doses with minimum interval of 4 weeks 1, 2
  • Only single-antigen varicella vaccine should be used (not MMRV) 1, 2

Select Immunocompromised Populations

• HIV-infected individuals with:

  • Asymptomatic or mildly symptomatic HIV infection
  • CD4 T-cell count ≥200 cells/mm³ in adults
  • CD4 T-cell percentage ≥15% in children aged 9 months-5 years 1

• Primary immune deficiency disorders without defective T-cell-mediated immunity:

  • Primary complement component deficiency disorders
  • Chronic granulomatous disease 1

• Patients planning to start immunosuppressive therapy:

  • Must receive vaccine ≥4 weeks before initiating therapy 1

Evidence of Immunity

Evidence of immunity to varicella includes any of the following 1, 2:

• Documentation of age-appropriate varicella vaccination
• Laboratory evidence of immunity or laboratory confirmation of disease
• Birth in the U.S. before 1980 (except for healthcare workers and pregnant women)
• History of varicella or herpes zoster diagnosed by a healthcare professional

High-Risk Groups for Prioritization

The following groups should be prioritized for vaccination if susceptible 1, 2:

• Healthcare workers
• Teachers and childcare employees
• Residents and staff in institutional settings
• College students and military personnel
• Nonpregnant women of childbearing age
• Adults living in households with children
• International travelers
• Household contacts of immunocompromised persons

Contraindications

Varicella vaccine should NOT be administered to:

• Pregnant women
• Severely immunocompromised patients, including:
  • Those with malignancies affecting bone marrow or lymphatic systems
  • Those receiving high-dose systemic steroids (>2 mg/kg/day of prednisone or equivalent for >2 weeks) 1
  • Patients with severe immunosuppression from any cause

Special Considerations

• Leukemia patients in remission: Vaccination should be undertaken only with expert guidance and availability of antiviral therapy 1
• Steroid therapy: Patients receiving <2 mg/kg or <20 mg/day of prednisone (or equivalent) may be vaccinated 1
• Post-steroid therapy: Patients who received high-dose steroids may be vaccinated once therapy has been discontinued for >1 month 1
• Household contacts of immunocompromised persons: Should be vaccinated to provide indirect protection 1

Vaccine Effectiveness

• Two-dose regimen provides significantly higher protection (98.3% efficacy) compared to single dose (94.4% efficacy) 1, 2
• Risk for breakthrough disease is 3.3-fold lower with two doses 1, 2
• Long-term studies show the vaccine provides protection for at least 7-10 years 3

Clinical Pearls

• Varicella disease is more severe in adolescents and adults, making vaccination of susceptible individuals in these age groups particularly important 1
• Serologic testing before vaccination is generally not necessary if a person lacks other evidence of immunity 2
• For immunocompromised patients who are eligible for vaccination, use only single-antigen varicella vaccine, not combination MMRV 1
• Breakthrough infections after vaccination are typically milder than natural disease 3