Changes in Genital Human Papillomavirus (HPV) Prevalence During 12 Years of Girls-Only Bivalent HPV Vaccination: Results From a Biennial Repeated Cross-sectional Study.

Abstract

Between 2009-2021, bivalent human papillomavirus (HPV) vaccination was offered to girls in the Netherlands. We studied the impact of girls-only HPV vaccination on genital HPV prevalence among young adults. PASSYON (2009-2021) is a study among sexual health clinic clients aged 16-24 years old. Questionnaires elicited data on demographics, sexual behavior, and HPV vaccination status. Genital samples were analyzed using a PCR-based assay (SPF10-LiPA25). Prevalence trends of 12 high-risk genotypes were assessed as adjusted average annual change (aAAC), estimated using Poisson generalized estimating equations models. The relation between aAAC and phylogenetic distance to HPV-16/18 was assessed by means of regression and rank correlation analysis. Data were collected from 8889 females and 3300 heterosexual males (HMs). Among females (irrespective of vaccination status), prevalences of HPV-16/18/31/33/35/45 decreased significantly over time. Increasing trends were observed for HPV-39/52/56. Among both HMs and unvaccinated females (54.3%), HPV-16/18 significantly declined, as did HPV-31 among HMs. Contrastingly, HPV-52/58 increased significantly among HMs and unvaccinated females. The type-specific aAAC correlated well with the phylogenetic distance to HPV-16/18. During 12 years of girls-only bivalent HPV vaccination in the Netherlands, decreasing trends of the vaccine types and cross-protected types were observed among females. Herd protection of vaccine types was observed for HMs and unvaccinated females, and 1 cross-protected type for HMs. Increasing prevalence trends of HPV types with large phylogenetic distance to the vaccine types might indicate type replacement.