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