This is a single-center, blinded, randomized and Gardasil-controlled (quadrivalent HPV vaccine GARDASIL®) Phase II clinical trial.~The trial will recruit a total of approximately 780 Chinese women 20-45 years of age with permanent residence. Healthy women ages 20-45 eligible for the trial will be stratified at a 1: 1 ratio into 2 age subgroups (20-30 years of age and 31-45 years of age), and each subgroup will be randomized at a 1: 1: 1 ratio to receive the mid-dosage investigational vaccine, high-dosage investigational vaccine or the positive control (quadrivalent HPV vaccine GARDASIL®), respectively.~Each subject will be administered 0.5 ml of the investigational vaccine or control in accordance with a 3-dose regimen at months 0, 2 and 6.~Peripheral blood samples of each subject will be collected at Day 0 (prior to dose 1), Month 7 (1 month post dose 3) to determine the levels of neutralizing antibodies and IgG antibodies to HPV types 6/11/16/18/31/33/45/52/58 in the sera. Optimal ratio of the antigens included in the investigational vaccine will be decided based on the immunogenicity and safety data from this trail.
This trail is to evaluate the safety profile of Recombinant Nonavalent (Types 6/11/16/18/31/33/45/52/58) Human Papillomavirus (HPV) Vaccine (Escherichia Coli) in healthy Chinese women ages 20-45 and determine the optimal ratio of the antigens included in the investigational vaccine. Besides, the trail is also to demonstrate that the levels of neutralizing antibodies to vaccine HPV types 31, 33, 45, 52 and 58 elicited by the investigational vaccine with the chosen optimal antigen ratio are superior to those induced by Gardasil.