[Development of an HPV vaccine--remaining issues and perspective].

Cervical cancer, the second most frequent gynecological malignancy in the world, is caused by infection with one of the 15 types of high-risk HPVs. Vaccines protecting women from infection with high-risk HPVs can reduce prevalence of cervical cancer. At present, two prophylactic vaccines (GlaxoSmithKline "Cervarix" and Merck "Gardasil") have been approved by several countries. These vaccines can almost completely protect HPV16 and 18 infections which account for approximately 50% and 20% of cervical cancer, respectively. However, cervical cancer screening should continue in all vaccinated women due to exposure of the other oncogenic HPV types. There are also unanswered remaining questions about overall vaccine effectiveness, duration of protection, and adverse effect.