Primary objective is to determine if antibody responses to HPV types 16 & 18 are non-inferior after a 2-dose paediatric regimen as compared to a 3-dose adult regimen of Q-HPV vaccination, with responses measured at Month 7.

Human Papillomavirus (HPV) infection is a cause of cervical cancer. Immunogenicity, safety and efficacy in the prevention of persistent infection from HPV 16 and 18 has been proven using a 3-dose regimen in adolescent and adult females using the Quadrivalent Human Papillomavirus (Q-HPV) vaccine. The intensity of the immune response is inversely proportional to age. Immunogenicity in adolescents 9-15 years of age is 1.7 - 2 times greater than in 16-26 year old vaccine recipients. Paediatric dosing studies are necessary and prudent given limited provincial funding for new biologics acquisition and programme service delivery. A reduction from an adult 3-dose HPV vaccine regimen to a pediatric 2-dose regimen will result in increased compliance to the full vaccine series and in significant savings to the health care system both in the cost of biologics and of program delivery and administration.

Inclusion Criteria:

• A female between, and including, 9-13 years (before 14th birthday) and 16-26 years of age (before 27th birthday) at the time of the first vaccination.
• Healthy
• Not pregnant
• Four or less sexual partners over lifetime as reported by subject. (Sexual activity is defined as intercourse)
• Not planning to become pregnant or likely to become pregnant
• No reported history of genital warts
• No laboratory confirmed history of cervical intraepithelial neoplasia
• No previous vaccination against HPV
• No administration of immunoglobulin and/or any blood products within the three months preceding the first dose of study vaccine or planned administration during the study period
• No previous anaphylactic reaction to HPV vaccine or any vaccine related component including aluminum hydroxyphosphate sulfate and polysorbate 80
• No confirmed or suspected immunosuppressive or immunodeficient condition based on medical history
• No bleeding diathesis or condition associated with prolonged bleeding time that would contraindicate intramuscular injection.
• Cannot be already enrolled in any clinical trial in which investigational vaccine or drug are being administered

Exclusion Criteria

• Pregnant
• Female planning to become pregnant or likely to become pregnant (as determined by the investigator) during the study duration Part 1 (0-7 months)
• Reported history of genital warts
• Laboratory confirmed history of cervical intraepithelial neoplasia
• Greater than four lifetime sexual partners involving sexual intercourse
• Previous vaccination against HPV
• Administration of immunoglobulin and/or any blood products within the three months preceding the first dose of study vaccine or planned administration during the study period
• A previous anaphylactic reaction to HPV vaccine or any vaccine related component including aluminum hydroxyphosphate sulfate and polysorbate 80
• Any confirmed or suspected immunosuppressive or immunodeficient condition based on medical history (e.g. HIV infection, genetic defect, immunosuppressive therapy). *Chronic administration (defined as more than 14 days) of immune-modifying drugs within 6 months prior to the first vaccine dose or planned use during the study period is exclusionary (corticosteroid use - immune-modifying level is ≥0.5 mg/kg/day; inhaled or topical steroids are acceptable).
• Bleeding diathesis or condition associated with prolonged bleeding time that would contraindicate intramuscular injection (thrombocytopaenia, coagulation disorder, anti-coagulant therapy).
• Enrollment in any clinical trial in which investigational vaccine or drug are being administered