Patient description: A Pap smear in a 54-year-old woman revealed abnormal cervical squamous intraepithelial/glandular lesion. She tested positive for HPV 16. She is sexually active with her husband and has 4 children. She is menopausal and uses no contraception. She smokes and drinks alcohol frequently. She is otherwise healthy. She was offered conization.

Clinical trial eligibility criteria: eligible ages (years): 15.0-25.0,  Infections, Papillomavirus Female between and including 15 and 25 years of age at the time of screening (must not have reached 26th birthday) Written informed consent obtained from the subject prior to enrolment (for subjects below the legal age of consent, written informed consent must also be obtained from a parent or legal guardian of the subject) Free of obvious health problems, as established by medical history and a directed physical examination No more than 6 lifetime sexual partners prior to enrolment Intact uterus Subject must be of non-childbearing potential, i.e., either surgically sterilised or, if of childbearing potential, she must be abstinent or must be using an effective method of birth control for 30 days prior to vaccination, have a negative urine pregnancy test and must agree to continue such precautions for two months after completion of the vaccination series For subjects not enrolled in the HPV epidemiology study (999910/106) and for subjects completing the study (999910/106) >90 days prior to enrolment in the present study: agreement to complete both entrance and exit study questionnaires concerning general personal information, and sexual, contraceptive, reproductive and other gynaecological medical history For subjects previously enrolled in the HPV epidemiology study (and who completed the study and an entrance questionnaire) ≤ 90 days prior to enrolment in the present study: agreement to complete the exit questionnaire only Normal cervical cytology (Pap smear) at screening, using the Cytyc ThinPrep® Pap Test. A normal Pap smear must also be adequate for interpretation, including the presence of endocervical cells; a Pap smear that is normal but inadequate for interpretation must be repeated as part of the protocol Seronegative for HPV-16 and HPV-18 antibody by ELISA at screening  Pregnant or lactating female Female planning to become pregnant during the first eight months of the study (months 0-8) Abnormal vaginal discharge at the time of entry (once these subjects have received therapy to eradicate any discharge they will be eligible to participate in study) Previous administration of any components of the investigational vaccine Chronic administration (defined as more than 14 days) of immuno-suppressants or other immune-modifying drugs within six months prior to the first vaccine dose Administration of immunoglobulin and/or any blood products within the three months (90 days) preceding the first dose of study vaccine or planned administration during the study period Planned administration / administration of a vaccine not foreseen by the study protocol within 30 days of the first dose of study vaccine. Administration of routine Meningococcal, Hepatitis A, Hepatitis B, Influenza, and Diphtheria/Tetanus vaccine up to 8 days before the first dose of study vaccine is allowed Use of any investigational or non-registered drug or vaccine other than the study vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period Receiving or expecting therapy for external or internal condylomata. Subjects with external condylomata not requiring therapy are eligible to participate in the study Genital herpes disease involving the cervix or characterized (on examination or by history) by extensive external lesions. Subjects with a history of recurrent genital herpes disease characterized by limited external lesions are eligible to participate in the study