BACKGROUND: To summarize HPV vaccine efficacy/effectiveness (VE) against anal HPV infection and anal intraepithelial neoplasia (AIN). METHODS: We performed literature review and meta-analysis to estimate VE stratified by age and analytic population (per-protocol efficacy [PPE] or intention-to-treat [ITT] population in clinical trials, or real-world studies). RESULTS: We identified 6 clinical trials and 8 real-world studies. In participants vaccinated at ≤ 26 years (mainly HIV-negative individuals), significant VE against incident/prevalent HPV infection was reported in clinical trials, with a higher estimate in PPE (2 studies; 2390 participants; VE 84%, 95%CI 77-90%; I2=0%) than ITT (2 studies; 4885 participants; 55%, 39-67%; 46%) or in real-world studies (4 studies; 2375 participants; 77%, 40-91%; 81%). HPV vaccination at ≤ 26 years was associated with significant VE in preventing persistent HPV infection and AIN. No significant VE against HPV infection or AIN in persons vaccinated >26 years (mainly people living with HIV [PLWH]) was found. CONCLUSION: There is strong evidence for high VE against anal HPV infection and AIN in HIV-negative individuals vaccinated aged ≤ 26 years. Lower impact in ITT than PPE populations, and lack of significant effect in PLWH >26 years, however, highlights greatest vaccine impact in populations more naïve to sexual exposure to anal HPV.
- Adults
- Adolescents
- Human papillomavirus (HPV)
- Efficacy/effectiveness
