Effect of prophylactic human papillomavirus L1 virus-like-particle vaccine on risk of cervical intraepithelial neoplasia grade 2, grade 3, and adenocarcinoma in situ: a combined analysis of four randomised clinical trials
Background Cervical cancer and its obligate precursors, cervical intraepithelial neoplasia grades 2 and 3 (CIN2/3), and adenocarcinona in situ (AIS), are caused by oncogenic human papillomavirus (HPV). In this combined analysis of four clinical trials we assessed the effect of prophylactic HPV vaccination on these diseases. Methods 20 583 women aged 16-26 years were randomised to receive quadrival