Two-dose varicella vaccination coverage among children aged 7 years--six sentinel sites, United States, 2006-2012.

In 2007, the Advisory Committee on Immunization Practices (ACIP) recommended a routine second dose of varicella vaccine for children at age 4-6 years, in addition to the first dose given at age 12-15 months. One strategy recommended for increasing varicella vaccination coverage is a school entry requirement of proof of varicella immunity. To determine the extent of implementation of the routine 2-dose varicella vaccination program, the number of states with a 2-dose varicella vaccination elementary school entry requirement in 2012 was compared with the number in 2007, and 2-dose varicella vaccination coverage during 2006 was compared with coverage in 2012 among children aged 7 years, using data from six Immunization Information System (IIS) sentinel sites. The number of states (including the District of Columbia) with a 2-dose varicella vaccination elementary school entry requirement increased from four in 2007 to 36 in 2012. Two-dose varicella vaccination coverage levels among children aged 7 years in the six IIS sentinel sites increased from a range of 3.6%-8.9% in 2006 to a range of 79.9%-92.0% in 2012 and were approaching the levels of 2-dose measles, mumps, and rubella (MMR) coverage, which had a range of 81.9%-94.0% in 2012. These increases suggest substantial progress in implementing the routine 2-dose varicella vaccination program in the first 6 years since its recommendation by ACIP. Wider adoption of 2-dose varicella vaccination school entry requirements might help progress toward the Healthy People 2020 target of 95% of kindergarten students having received 2 doses of varicella vaccine.