Abstract
Background: Despite a reduction in the prevalence of vaccine-preventable types of human papillomavirus (HPV), attributed to increased HPV vaccine uptake, HPV continues to be a major cause of cancer in the United States. Methods: We assessed factors associated with self-reported HPV vaccine uptake, HPV vaccination effectiveness, using DNA testing to assess HPV types 16 and/or 18 (HPV 16/18) positivity, and patterns of HPV vaccination in 375 women aged 21-29 years who were eligible to receive catch-up vaccination, using baseline data collected from March 2012 to December 2014 from a randomized controlled trial evaluating a novel approach to cervical cancer screening. Results: More than half (n = 228, 60.8%) of participants reported receipt of at least one HPV vaccine dose and 16 (4.3%) tested positive for HPV 16/18 at baseline. College-educated participants were four times more likely to have been vaccinated than those reporting high school education or less. 56.5% of HPV-vaccinated participants reported first dose after age 18 and 68.4% after first vaginal intercourse. Women vaccinated after age 18 and women vaccinated after first vaginal intercourse were somewhat more likely to be infected with HPV 16/18 infection compared with women vaccinated earlier, but these associations did not reach statistical significance. Conclusions: HPV vaccination is common among college-educated women in the catch-up population but less common among those without college education. Contrary to current guidelines, catch-up females frequently obtain HPV vaccination after age 18 and first vaginal intercourse. Women without a college education represent an ideal population for targeted HPV vaccination efforts that emphasize vaccination before sexual debut.