•Demonstrate the efficacy of the candidate vaccine, human papillomavirus 16/18 (HPV 16/18) L1 virus-like particle (VLP)/AS04 vaccine compared with control in preventing grade 2 or 3 cervical intraepithelial neoplasia, adenocarcinoma in situ of the cervix, or invasive cervical cancer (CIN2+) associated with HPV 16 or HPV 18 cervical infection in younger healthy participants who are negative for HPV DNA by polymerase chain reaction (PCR) for the corresponding HPV type at months 0 and 6.