Concomitant Adolescent Vaccination in the U.S., 2007-2012.

INTRODUCTION Concomitant (same-day) delivery of two or more vaccines to adolescents is effective, safe, and efficient. Increasing concomitant vaccination could improve coverage for recommended adolescent vaccines, but little is known about who receives vaccines concomitantly. METHODS Data came from healthcare provider-verified records on 70,144 adolescents (aged 13-17 years) in the 2008-2012 versions of the National Immunization Survey-Teen who had received at least one dose of tetanus, diphtheria, and acellular pertussis (Tdap) booster; meningococcal conjugate vaccine (MenACWY); or human papillomavirus (HPV) vaccine. Separately for each vaccine, multivariable logistic regression identified adolescent and household correlates of concomitant versus single vaccination, stratified by adolescent sex. Vaccination took place in 2007-2012, data collection in 2008-2012, and data analysis in 2015. RESULTS Among vaccinated adolescents, 51%-65% of girls and 25%-53% of boys received two vaccines concomitantly. Concomitant uptake of each vaccine increased over survey years (e.g., 2012 vs 2008: girls' Tdap booster, OR=1.88, 95% CI=1.56, 2.26; boys' Tdap booster, OR=2.62, 95% CI=2.16, 3.16), with the exception of HPV vaccination among boys. Additionally, concomitant vaccination was less common as adolescents got older and in the Northeast (all p<0.05). For MenACWY and HPV vaccine, concomitant uptake was less common for girls whose mothers had higher versus lower education and for boys who lived in metropolitan versus non-metropolitan areas (all p<0.05). CONCLUSIONS Missed opportunities for concomitant adolescent vaccination persist, particularly for HPV vaccine. Future interventions targeting groups with low rates of concomitant vaccination could improve population-level coverage with recommended vaccines.