Reduction in vaccine-type HPV infections in a group of young women (18-25 years old) five years after HPV vaccine introduction in Colombia.

Abstract

BACKGROUND/OBJECTIVES\nIn Colombia, the HPV vaccine was launched in 2012 in the context of a school-based national vaccination program targeting girls aged 9-14 and offering catch-up vaccination for girls aged 14-17. In this study, we evaluated the program s impact on type-specific HPV infection by comparing HPV cervical prevalence among vaccinated and unvaccinated women.\n\n\nMETHODS\nThis is a comparative cross-sectional study conducted five years after the implementation of the quadrivalent HPV vaccine in a sentinel city in Colombia. This study included young women (18-25 years old) who had catch-up vaccination and were attending universities and technical institutions, and women who attended primary health care facilities for Pap smear screening. The HPV prevalence of 1287 unvaccinated women was compared with prevalence in 1986 vaccinated women.\n\n\nRESULTS\nThe prevalence of HPV 16/18 infections was significantly lower in vaccinated compared to unvaccinated women (6.5% vs 15.4%; p<0.001), whereas for HPV 6/11 infections, a decrease of 63.7% was observed in vaccinated women (1.02% vs 2.81%). The adjusted vaccine effectiveness for HPV 16/18 was 61.4% (95% CI: 54.3-67.6%). However, effectiveness against HPV 16/18 was significantly higher among women vaccinated before their sexual debut (91.5%; 95% CI: 86.8-94.5%), compared to vaccine effectiveness after sexual debut (36.2%; 95% CI: 23.6-46.7%).\n\n\nCONCLUSIONS\nFive years after the introduction of HPV vaccines in Colombia, high effectiveness of HPV to prevent HPV 16/18 infections are observed in the catch-up cohorts, including virgin and sexually active women.