This phase Ⅱ clinical study was designed to evaluate the immunogenicity and safety of the novel recombinant HPV type 6/11 bivalent vaccine, manufactured by Xiamen Innovax Biotech CO., LTD., in healthy volunteers aged 18-55 years of age at enrollment. The study volunteers would be randomized to receive the 3 different formulations of the novel HPV vaccine or placebo vaccine (recombinant hepatitis E vaccine) administered intramuscularly according to a 0-1-6 month schedule. This is a double-blind study.