What are the Indian Academy of Pediatrics (IAP) guidelines for varicella vaccine administration in infants?

IAP Guidelines for Varicella Vaccine in Babies

Primary Vaccination Schedule

All healthy infants should receive their first dose of varicella vaccine at 12-15 months of age, followed by a second dose at 4-6 years of age, with a minimum interval of 3 months between doses. 1, 2

First Dose Timing

• The varicella vaccine is approved for use starting at 12 months of age and should be administered routinely between 12-15 months 1, 2
• This timing aligns with other routine childhood immunizations and ensures early protection during the vulnerable toddler years 1
• The vaccine should not be given before 12 months of age as it is not licensed for younger infants 2

Second Dose Timing

• The second dose is routinely recommended at 4-6 years of age (before entering kindergarten or first grade) 1, 2
• However, the second dose may be administered at an earlier age if needed, provided the minimum 3-month interval is maintained 1, 2
• If the second dose is inadvertently given between 28 days and 3 months after the first dose, it does not need to be repeated 1, 2

Dosing Intervals and Administration

Minimum Interval Requirements

• For children 12 months through 12 years: minimum 3-month interval between doses (recommended interval) 1, 2
• The absolute minimum acceptable interval is 28 days, though 3 months is preferred based on clinical trial design 1, 2
• For adolescents and adults ≥13 years: minimum 28-day interval between doses 1, 2

Route and Dose

• Administer 0.5 mL subcutaneously for each dose 1
• Both monovalent varicella vaccine and MMRV combination vaccine are licensed for children 12 months through 12 years 1
• The vaccine must be stored frozen at -15°C and used within 30 minutes after reconstitution 1

Concomitant Vaccine Administration

Varicella vaccine can be safely administered simultaneously with other routine childhood vaccines without compromising immunogenicity. 1

• Concomitant administration with DTaP, Hib, and hepatitis B vaccines produces comparable seroconversion rates to individual administration 1
• May be given simultaneously with vaccines recommended for children 12-15 months and 4-6 years of age 1
• This approach minimizes the number of clinic visits and ensures timely protection 1

Immunogenicity and Efficacy

Two-Dose Schedule Benefits

• Seroconversion rate: 93.3% after first dose, 100% after second dose in Indian children 3
• Two doses provide 98% vaccine efficacy compared to 94% for a single dose 2
• Recipients of 2 doses are 3.3-fold less likely to experience breakthrough varicella 2
• After two doses, >99% of children achieve protective antibody levels 2

Indian Context

• A study in Indian children (mean age 4.4 years) demonstrated that the two-dose schedule administered 3 months apart was safe and highly immunogenic 3
• High GMT levels (9-fold increase) were observed from post-first-dose to post-second-dose across all age groups 3
• Only one mild breakthrough infection occurred after close contact with a severe case 3

Contraindications and Precautions

When NOT to Vaccinate

• Evidence of immunity to varicella-zoster virus (prior documented disease or seropositivity) 1
• Immunocompromised children (though special protocols exist for leukemia patients in remission) 4
• Pregnancy (vaccine contains live virus) 1
• Severe allergic reaction to previous dose or vaccine component 1

Documentation Requirements

• Only written documentation of vaccination date is considered valid evidence of immunity 1
• Self-reported vaccination history or parental recall alone is insufficient 1
• Healthcare professionals should provide immunization records documenting administered vaccines 1

Special Considerations for India

Public Health Context

• Varicella outbreaks in India occur at younger ages, making early two-dose vaccination particularly important 3
• The disease can be severe with complications including bacterial infections (up to 5%), pneumonia, and encephalitis (1 in 10,000 cases) 5
• Universal vaccination can dramatically reduce incidence, complications, hospitalizations, and fatality rates 5

Cost-Effectiveness

• Both 1-dose and 2-dose programs are cost-saving at the societal level 1
• The incremental cost for the second dose is $96,000 per quality-adjusted life-year saved 1
• When benefits from preventing secondary complications are included, cost-effectiveness improves further 1

Catch-Up Vaccination

For Unvaccinated Children

• Children who missed vaccination at 12-15 months should begin the two-dose series immediately 2
• The series does not need to be restarted regardless of time elapsed 2
• Adolescents 11-12 years should have immunization status evaluated and receive necessary doses 1