Levels of varicella vaccination coverage with ≥2 doses and the proportion of adolescents with evidence of immunity increased from 2007 to 2014, though 16% lacked evidence of immunity in 2014, according to a recent study. Although catch-up campaigns have succeeded, missed vaccination opportunities persist. Researchers used data from the 2007-2014 National Immunization Survey–Teen (NIS-Teen), which collects information on adolescents aged 13 to 17 years in the US. They found:
- From 2007 to 2014, varicella vaccination coverage with ≥2 doses increased from 8.3% to 66.9% in 13- to 15-year-olds and from 3.6% to 56.7% in 16- to 17-year-olds.
- The proportions with evidence of immunity also increased from 68.0% to 84.1% (13- to 15-year-olds) and 78.6% to 83.4% (16- to 17-year-olds).
- In 2014, 13.4% of 13- to 15-year-olds and 3.2% of 16- to 17-year-olds had received their second dose at 4 to 6 years of age.
- Factors most significantly associated with lower coverage with ≥2 doses were not having an 11- to 12-year well-child visit, not receiving an adolescent vaccine, and residence in a state with no 2-dose immunization school entry requirement.
Leung J, Reagan-Steiner S, Lopez A, Jeyarajah J, Marin M. Varicella vaccination among US adolescents: Coverage and missed opportunities, 2007-2014. [Published online ahead of print June 7, 2018]. J Public Health Manag Pract. doi:10.1097/PHH.0000000000000819.
In the US, varicella vaccine was recommended as a single dose in 1995. Later, in 2006, a second dose was recommended, after evaluation of data on varicella outbreaks. Before the current vaccine era, there were 4 million cases and 100-150 deaths per year in the US from varicella. This study shows an impressive improvement in 2-dose coverage of adolescents over time. However, the study identifies significant missing opportunities to provide the second dose which could be targeted in the future, such as advocating for all states to have a 2-dose school entry requirement.—Sarah Rawstron, MB, BS, FAAP, FIDSA; Pediatric Residency Program Director, The Brooklyn Hospital Center, NY; Clinical Associate Professor, Icahn School of Medicine, Mount Sinai, NY.