Infection with human immunodeficiency virus (HIV) is an important risk factor for HPV infection and the development of HPV-associated lesions in female and male anogenital tract. Data on safety and immunogenicity of quadrivalent human papillomavirus vaccine in HIV-infected population are few. The present study is a non-randomized controlled clinical trial with the primary objective to determine safety ad immunogenicity of quadrivalent human papillomavirus vaccine (Gardasil®) in HIV-infected female and male adolescents and young adults.

Inclusion Criteria:

• For both HIV-infected and healthy subjects:

  • Subjects aged 13-27 years, females and males
  • Written informed consent from parent or guardian if applicable (age<18 years)

• For HIV-infected subjects:

  • HIV-positive
  • Asymptomatic subjects (generalized lymphadenopathy is accepted)
  • Lymphocyte CD4+ count > or equal to 350 cells/mm3

• For subjects receiving HAART:

  • Good compliance to therapy
  • At least two suppressed viral loads HIV-RNA (<37copies/ml9 during 6 months prior to enrollment.

Exclusion Criteria:

• For female subjects (both HIV-infected and healthy)
• Pregnancy or breastfeeding
• Total hysterectomy. Participants who have undergone partial hysterectomy and have a cervix are not excluded.
• For both females and males (HIV-infected and healthy):
• Prior vaccination with quadrivalent HPV vaccine Gardasil before study entry.
• History of severe allergic reaction after previous vaccination or hypersensitivity to any vaccine component.
• Any serious chronic or progressive disease (other than HIV) according to the judgment of the investigator:
• Acute infection requiring therapy or fever at time of enrollment
• Chronic autoimmune or oncologic disease receiving chemotherapy
• Concomitant therapies (other than HAART):
• Chronic therapy (for more than 14 days consecutively) with immunosuppressive or immunomodulating agents or chemotherapy during the 6 months prior to study entry.
• Receipt of blood, blood products and/or plasma derivatives or any parenteral immunoglobulin preparation prior to study entry.
• Use of investigational agents within 4 weeks prior to study enrollment.
• Current drug or alcohol use or dependence.
• Documented history of non-adherence to antiretroviral treatment regimen within 12 months prior to study entry.