Expanding HPV prevention across the life course: evidence on vaccine effectiveness in adults.

Despite Human Papillomavirus (HPV) remaining a major global public health concern and affecting all age groups and genders, most HPV vaccination programmes mainly target female adolescents. This narrative review synthesizes and critically discusses recent evidence on the effectiveness of HPV vaccination among adults to inform its integration into adult immunization programmes. A substantial body of recent literature has examined the effectiveness of HPV vaccination in adult populations. Across the literature, vaccine effectiveness has been evaluated in relation to (1) HPV infection and viral dynamics, (2) precancerous cervical lesions (HSIL/CIN), (3) prevention of post-treatment recurrence, (4) HPV-related cancers, and (5) anogenital warts. Some associations were found between HPV vaccination and reduced HPV infection and viral persistence, whilst effect estimates varied widely across studies for high-grade cervical lesions (CIN2+). This review aims to characterize the effectiveness of the HPV vaccination amongst adults (18-45 years) in preventing human papillomavirus infections and HPV related disease outcomes. By synthesizing and evaluating recent evidence on HPV vaccine efficacy, we aim to assess its relevance in expanding HPV vaccination within life-course immunization programs.