Kayla E Hanson’s scientific contributions

Background: HPV vaccination uptake remains lower than other recommended adolescent vaccines in the United States. Parental attitudes are important predictors of vaccine uptake, yet little is known about how they have changed over time. Methods: Participants included U.S. residents aged 13-17 years with documented vaccination status who were unvaccinated (had not initiated) or undervaccinated (initiated, but had not completed) with the HPV vaccination series whose parents responded to the National Immunization Surveys-Teen, 2010-2015. Results: Of the 76,971 participants, 63.0% were male, 58.8% were non-Hispanic white, and 14.4 years was the median age. The percentage of unvaccinated teens decreased 2010-2015, yet, annually, parents of unvaccinated teens of both sexes most often reported that they were "not likely at all" to vaccinate their teen. The percentage decreased significantly from 41.5% to 31.2% (P<.001) for parents of unvaccinated females from 2010-2015 but did not change among parents of males from 2012-2015. Conversely, parents of undervaccinated teens of both sexes reported higher and increasing vaccination intent over time. In 2015, nearly one third of parents of unvaccinated teens reported that their low intent stemmed from the belief that the vaccine was "not needed/necessary." Concerns about vaccine safety and side effects declined over time among parents of unvaccinated females but increased among parents of males (7.3% to 14.8%; P<.001). Conclusions: Although parental intent and knowledge increased over time, lack of perceived importance of HPV vaccination and parental concerns about vaccine safety remain barriers to both HPV vaccination series initiation and completion in the U.S.