Vaccines for preventing HPV-related anogenital infection and neoplasia.

Human papillomavirus (HPV) is a common sexually transmitted pathogen. Although most anogenital HPV infections resolve within several years, persistent infection may lead to neoplasia of the cervix, vagina, vulva, anus, and penis, and also genital warts. High-risk HPV types 16 and 18 are known to cause approximately 70% of all cervical cancers, and low-risk HPV types 6 and 11 are the main causes of genital warts. Prophylactic HPV vaccines have the potential to block the acquisition of HPV and hence subsequent development of anogenital neoplasia. Results from several clinical trials have demonstrated that the HPV L1 virus-like-particle vaccines are safe and highly immunogenic. These trials have documented a 100% vaccine efficacy in prevention of persistent HPV infection and, more important, of HPV-associated anogenital neoplasia in per-protocol analyses. Widespread vaccination of sexually naïve preadolescent children could substantially reduce the morbidity and mortality associated with anogenital malignancies. Furthermore, such a primary prevention program would also reduce healthcare costs.