Immune Response to Bivalent and Tetravalent Human Papillomavirus Vaccine in HIV Infected Adults

Inclusion Criteria: * HIV positive subjects. * Age above 18 at the time of the first vaccination. * Written informed consent obtained from the subject. * Subjects whom the investigator believes can and will comply with the requirements of the protocol. * If currently on antiretroviral therapy (ART), subjects must be compliant to triple therapy (highly active ART) and have undetectable viral load for a period of six months prior to study entry. * Female subjects of non-childbearing potential may be enrolled in the study. * Female subjects of childbearing potential may be enrolled in the study, if the subject has a negative pregnancy test at screening and on the day of vaccination, and has agreed to continue adequate contraception during the entire treatment period. Exclusion Criteria: * Previous vaccination against HPV, or planned administration of any HPV vaccine other than that foreseen by the study protocol during the study period (Day 0 to Month 12). * Pregnant or breastfeeding female. * Previous enrollment in the study. * Subjects whom the investigator believes cannot and/or will not comply with the requirements of the protocol (i.e. because of abuse of drugs or alcohol, dementia or given medical, psychiatric, social or work related conditions). * Chronic administration of immunosuppressive drugs * Cancer or autoimmune disease * Previous allergic reaction to vaccination * Known allergy towards on or more components of either of the test drugs.