At what age do children receive the varicella (chickenpox) vaccine?

Varicella (Chickenpox) Vaccine Timing for Children

Children should receive their first dose of chickenpox vaccine at 12-15 months of age, followed by a second dose at 4-6 years of age. 1

Primary Vaccination Schedule

First Dose

• The first dose is routinely administered at 12-15 months of age for all healthy children, as recommended by the American Academy of Pediatrics and CDC. 1
• The vaccine is approved for use starting at 12 months of age—do not administer earlier than this. 1
• There is no evidence that delaying vaccination within the 12-18 month window affects vaccine effectiveness, so vaccination at 12 months is appropriate and effective. 2

Second Dose

• The second dose is routinely given at 4-6 years of age, ideally before entering prekindergarten, kindergarten, or first grade. 1
• This timing is strategically chosen because varicella outbreaks are more common among elementary school-aged children compared to preschoolers. 1
• The second dose may be administered earlier than 4-6 years if needed, as long as the minimum 3-month interval from the first dose is maintained. 1

Minimum Intervals Between Doses

• For children 12 months through 12 years: minimum 3-month interval between doses is required. 1
• If the second dose is inadvertently given between 28 days and 3 months after the first dose, it does not need to be repeated—this is acceptable. 1
• For adolescents and adults 13 years and older: minimum 4-week (28-day) interval between doses. 1, 3

Catch-Up Vaccination

• Children who missed the routine schedule should start the two-dose series immediately—there is no need to restart regardless of time elapsed. 1
• For a 7-year-old who has never been vaccinated: give the first dose at the current visit and schedule the second dose 3 months later. 1
• For adolescents who received only one dose as a child: administer the catch-up second dose with a minimum 4-week interval. 3

Available Vaccine Formulations

• Monovalent varicella vaccine (Varivax): approved for ages ≥12 months and can be used at any age. 1
• Combination MMRV vaccine (ProQuad): only approved for ages 12 months through 12 years—cannot be used in adolescents or adults. 1, 3
• For persons ≥13 years: only single-antigen varicella vaccine may be used. 1, 3

School Entry Requirements

• All children entering school must have received two doses of varicella vaccine or have other evidence of immunity. 1
• The implementation of two-dose school entry requirements has dramatically increased coverage, with rates rising from 3.6-8.9% in 2006 to 79.9-92.0% in 2012 in sentinel sites. 4

Clinical Rationale for Two-Dose Schedule

• Two doses provide 98% vaccine efficacy compared to 94% for a single dose—a clinically meaningful difference. 1
• Recipients of two doses are 3.3-fold less likely to experience breakthrough varicella compared to those receiving only one dose. 1
• After two doses, >99% of children achieve protective antibody levels, compared to only 76-85% after a single dose. 1