Objective: The purpose of this study was to inform policy regarding human papillomavirus (HPV) vaccination in North America. We measured the clinical impact of HPV-6/-11/-16/-18 vaccination in North American women.
Study design: The study enrolled 21,954 women, the majority aged 16-25, across 5 studies of a quadrivalent HPV vaccine or its HPV-16 vaccine prototype. The North American subjects (n = 5996) were pooled from these trials, and the prevalence of HPV-6/-11/-16/-18 exposure was measured. The impact of vaccination on the burden of anogenital HPV lesions in an intention-to-treat population (regardless of enrollment HPV status) was calculated.
Results: At enrollment, the median age was 20 years; 13% of the women had had a Papanicolaou test abnormality, and 76% of the women had negative tests results for all 4 vaccine HPV types. With approximately 3 years of follow-up evaluations in the intention-to-treat population (regardless of enrollment HPV status), vaccination reduced the rate of HPV-16- and -18-related precancers and HPV-6/-11/-16/-18-related genital lesions by 66.4% (95% CI, 42.7%-81.1%) and 57.7% (95% CI, 27.3%-76.3%), respectively.
Conclusion: The administration of HPV vaccine to sexually active North American women reduced the burden of HPV-6/-11/-16/-18-related disease. Catch-up vaccination programs in this population are warranted.