Human Papillomavirus Vaccination and Anogenital Warts: A Systematic Review of Impact and Effectiveness in the United States.

ABSTRACT

BACKGROUND: Assessing the impact and effectiveness of HPV vaccines on anogenital warts in the United States can provide early indication of the success of vaccination programs as well as identify potential areas for improvement. METHODS: Articles were identified from the PubMed, Medline, and Embase databases. Exclusion criteria were applied, and remaining studies were then classified as impact or effectiveness studies. RESULTS: Eight eligible studies published through March 2018 were included. Population-based impact studies examining trends in diagnoses reported consistent declines in females ages 25 years and younger after 2006 when routine female vaccination began in the United States. Declines in males ages 25 years and younger were also seen; however, these declines were lower than those in females and more evident after routine male vaccination began in 2011. Among females and males older than 25 years, little to no change has been seen in the trends of anogenital warts since 2006. Studies that included the pre-vaccine era (before 2006) reported increasing trends during this period. After vaccine introduction, a reversal in these trends was observed. Effectiveness studies that included individual-level vaccination histories consistently demonstrated a lower risk of anogenital warts for those receiving at least one dose of the vaccine compared to those unvaccinated. CONCLUSIONS: These findings suggest that the degree of HPV vaccine impact has varied substantially by age and sex. Achieving the full prevention potential of HPV vaccines will likely require greater coverage among both females and males. Post-licensure estimates of effectiveness demonstrate the real-world benefit of the vaccine.