Vaccine effectiveness following routine immunization with bivalent HPV vaccine: Protection against incident genital HPV infections from a reduced-dosing schedule
Menée aux Pays-Bas par questionnaire et à l'aide de prélèvements vaginaux collectés auprès de 2 027 jeunes filles, cette étude analyse l'efficacité, 4 ans après la vaccination contre le papillomavirus humain, de deux doses du vaccin bivalent préconisé par le programme national depuis 2014
In the Netherlands, the bivalent HPV vaccine (2vHPV) has been offered to preadolescent girls via the National Immunization Program (NIP) in a two-dose (2D) schedule since 2014. The current study estimates vaccine effectiveness (VE) against HPV infections up to four years post-vaccination among girls eligible for routine 2D immunization.A cohort study (HAVANA2) was used in which participants annually filled out an online questionnaire and provided a vaginal self-sample for determination of HPV by the SPF10-LiPA25 assay, able to detect 25 HPV types. VE against incident type-specific infections and pooled outcomes was estimated by a Cox proportional hazards model with shared frailty between the HPV types.In total, 2027 girls were included in the study, 1098 (54.2%) of whom were vaccinated with two doses. Highest incidence rate was 5.0/1000 person-years (HPV51) among vaccinated participants and 9.1/1000 person-years (HPV74) among unvaccinated participants. Adjusted pooled VE was 84.0% (95%CI, 27.0-96.5%) against incident HPV16/18 infections and 86.5% (95%CI, 39.5-97.08%) against cross-protective types HPV31/33/45.Four years post-vaccination, two doses of 2vHPV vaccination were effective in the prevention of incident HPV16/18 infections and provided cross-protection to HPV31/33/45. Our VE estimates rival those from three-dose schedules, indicating comparable protection by 2D schedules.