Association between human papillomavirus vaccine status and sexually transmitted infection outcomes among females aged 18-35 with a history of sexual activity in the United States: A population survey-based cross-sectional analysis

Background: Current human papillomavirus (HPV) vaccine coverage in the United States (in 2019, 66–70%), remains below the Healthy People 2020 coverage goal of 80%. HPV vaccine misinformation, including parental concerns of sexual risk-compensation influence vaccine uptake. We examined the association between HPV vaccination and sexually transmitted infection (STI) outcomes. Methods: Of the 20,146 participants from 2013 to 2014 and 2015–2016 cycles of the National Health and Nutrition Examination Survey, 1050 females aged 18–35 with a history of sexual activity had complete case data. Roa-Scott Chi-squared and F-tests assessed survey-weighted socio-demographic differences between vaccinated and unvaccinated participants. Weighted logistic regression assessed crude and adjusted associations between self-reported HPV vaccination (none vs. ≥ 1dose) and lab-confirmed STIs (trichomonas and chlamydia) and vaccine-type HPV (6/11/16/18). As a sensitivity analysis, we conducted weighted-propensity score (PS) models and inverse probability weighting by vaccination status. PS and logistic regression were estimated through survey-weighted logistic regression on variables including race, education, income, marital status, US citizenship, cycle year and age. Results: Overall, 325 (31.8%) females with a history of sexual activity were HPV vaccinated, of which 22 (6.1%) received the vaccine at the routine-recommended ages of 11–12, 65.7% were vaccinated after their self-reported sexual debut, 3.8% had a lab-confirmed STI and 3.5% had vaccine-type HPV. There was no association between HPV vaccination and any STIs (adjusted odds ratio [aOR] 0.67, 95%CI:0.38–1.20), and vaccinated participants had 61% reduced odds of vaccine-type HPV (vs. unvaccinated; aOR 0.39, 95%CI:0.19–0.83). Results from the PS sensitivity analysis were similar to the main findings. Conclusion: Among females who reported a history of sexual activity, HPV vaccination status was protective against vaccine-type HPV and not associated with lab-based STI outcomes. Although findings may be susceptible to reporting bias, results indicating low vaccine uptake at routine-recommended ages requires additional efforts promoting HPV vaccination before sexual-debut.