Effects of two and three vaccinations with the bivalent HPV vaccine on the prevalence and load of HPV in clearing and persistent infections in young women

Abstract

Human papillomavirus viral load (HPV VL) is associated with persistence, which increases cervical cancer risk. The bivalent vaccine protects against oncogenic HPV16/18 and cross-protects against several non-vaccine types. We examined the effect of two-dose (2D) and three-dose (3D) vaccination on HPV prevalence and viral load in clearing (CIs) and persistent infections (PIs), 6y and 12y post-vaccination, respectively. Vaginal swabs collected from HPV Among Vaccinated And Non-vaccinated Adolescents (HAVANA, 3D-eligible) and HAVANA-2 (2D-eligble) participants were genotyped for HPV with the SPF₁₀-DEIA-LiPA₂₅. HPV VL was measured with type-specific qPCRs. HPV16, 18, 31, 33 and 45 CI and/or PI prevalence and HPV16, 18, and 31 VLs in CIs were significantly reduced in 3D vaccinated women compared to unvaccinated women. Except for HPV11 and HPV59 CIs, no significant VL differences were observed among vaccinated women, ≤6y and >6y post-vaccination. Infection numbers were low in 2D-eligible women, with no HPV16 and 18 in vaccinated women. No VL differences for the remaining types were found. 3D vaccination reduces HPV prevalence in CIs and PIs and decreases HPV VLs in CIs, 12y post-vaccination for vaccine and several non-vaccine types. 2D-eligible women had low infection numbers, with no HPV16/18 among vaccinated women.