Two-dose varicella vaccination rates increased since 2007
The number of states that implemented the two-dose varicella vaccination elementary school entry requirement increased from four in 2007 to 36 in 2012, according to a recent MMWR.
“The increases suggest substantial progress in implementing the routine two-dose varicella vaccination program in the first 6 years since its recommendation by ACIP,” the researchers wrote. “Wider adoption of two-dose varicella vaccination school entry requirements might help progress toward the Healthy People 2020 target of 95% of kindergarten students having received two doses of varicella vaccine.”
ACIP recommended a routine second dose of varicella vaccine for children aged 4 to 6 years in 2007. Researchers used data from six Immunization Informing System sentinel sites to determine two-dose varicella vaccination coverage levels among children aged 7 years. In 2006, two-dose vaccination levels ranged from 3.6% to 8.9% in children aged 7 years compared with 79.9% to 92% in 2012.
Valid doses were defined as those administered no earlier than 4 days before aged 1 year for dose one and the second dose as at least 28 days after the first dose, or either dose administered the same day or 4 or more weeks after another live vaccine.
All but one of the 36 states required one or more doses of varicella vaccination before school entry by the 2012 to 2013 school year. Two-dose coverage was slightly higher in the four states that required two-doses before school entry (Michigan, Minnesota, North Dakota and Wisconsin), and lower than those sites with a one-dose requirement (New York City and Oregon), but it was not statistically significant (P=.5).
“The one-dose varicella vaccination program, implemented in 1996, resulted in 70% to 90% declines in varicella disease incidence, hospitalizations, and mortality,” the researchers wrote. “The routine two-dose varicella vaccination program was implemented to further decrease varicella disease and control outbreaks. Since its implementation in 2007, declines in varicella incidence and outbreaks ranging from 67% to 76% have been reported. Further declines in varicella incidence and outbreaks might occur as higher two-dose varicella vaccination coverage is achieved.”
Disclosure: The researchers report no relevant financial disclosures.