Prevention of human papilloma virus-induced preneoplasia and cancer by prophylactic HPV vaccines.

Persistent infection with human papilloma virus (HPV) is a necessary condition for the development of cervical, most of the vulvar and anal carcinoma and their precursors. HPV is the most common sexually transmitted virus throughout the world. About 70-80% of sexually active people are infected during their lifetime. Most infections are transient and asymptomatic and cleared by the host immune system within 12-18 months. Only persistent infections predispose to the development of genital preneoplasia and cancer. The first vaccine against HPV infection has been available in Italy since March 2006. The vaccine is a prophylactic, quadrivalent vaccine against the two most common oncogenic HPV types 16 and 18, responsible for more than 70% of cervical carcinomas and against the two low-risk types 6 and 11 responsible for 90% of cases of genital warts. A second, bivalent HPV 16/18 vaccine will be launched soon. The immunogenicity (100%) and efficacy of the vaccines is very high (96% against infection, 100% against disease). These vaccines constitute a milestone in the battle against cervical carcinoma, which is the second most common cancer in young women in Europe, with 33,500 new cases diagnosed every year.