July 24, 2017
A new study led by UNC Gillings School of Global Public Health epidemiologists is the first to utilize a large insurance claim database to assess co-administration of recommended adolescent vaccines.
The study indicates that too few adolescents in the United States are obtaining recommended prophylactic vaccines against human papillomavirus (HPV), a known and preventable cause of cervical and other cancers in females and males, as compared with vaccines against tetanus-diphtheria-acellular pertussis (Tdap), and meningitis (MenACWY).
Nadja Vielot, PhD, 2017 alumna of the Gillings School, is lead author, and Jennifer S. Smith, PhD, professor of epidemiology, is senior author of the study, which was published online July 22 in the Journal of Adolescent Health.
Using data from MarketScan insurance claims from 2009 to 2014, Vielot, Smith and colleagues identified nearly 1.7 million 11-year-olds who had insurance coverage during the study period. They estimated the proportions of adolescents who received recommended vaccines, examined the timeliness of those vaccinations and estimated associations with the adolescents’ geographical locations.
By a large margin over the five-year follow-up period, more adolescents received vaccinations for Tdap (52.1 percent) and MenACWY (45.8 percent) than for HPV (18.4 percent). On average, adolescents received HPV vaccination at a later age than either Tdap and MenACWY.
Those most likely to initiate HPV vaccination were girls, adolescents living in the western U.S. or those living in urban areas. Southern adolescents were least likely to receive HPV vaccination, and rural adolescents (except in the Northeast) were less likely to receive any of the three vaccines than those in urban areas.
Timely HPV vaccination, i.e., vaccination at age 11 or 12, as recommended by the Centers for Disease Control and Prevention (CDC), also was positively associated with female gender, living in an urban setting or living in the western U.S.
“HPV vaccination rates were dwarfed by those of either Tdap or MenACWY in more than 1.7 million adolescents with employer-sponsored insurance,” Smith said. “These data confirm frequent missed clinical opportunities to provide HPV vaccination for the future prevention of HPV-associated cancers to adolescents receiving other nationally recommended vaccines.”
“We identified some interesting disparities in HPV vaccination rates by region, wherein rural adolescents appeared to have more barriers to HPV vaccination,” Vielot said. “It will be critical to identify where these barriers lie, either with respect to parental acceptability, accessibility of vaccines or strength of provider recommendations for HPV vaccination. At present, providers are encouraged to strongly recommend all vaccines to all eligible adolescents, using the messaging endorsed by the CDC.”
The authors found increased rates of co-administration of the Tdap, MenACWY and HPV vaccines among adolescents who were born more recently. The researchers suggest that vaccine co-administration is a useful way to increase vaccination coverage. They recommend that health-care providers encourage vaccine co-administration and HPV vaccination for all their age-eligible adolescent patients.
Other UNC-Chapel Hill co-authors are Anne Butler, PhD, former postdoctoral fellow in epidemiology, and Alan Brookhart, PhD, professor of epidemiology (both at the Gillings School); and Sylvia Becker-Dreps, MD, MPH, associate professor of family medicine at the UNC School of Medicine.