To evaluate the immune non-inferiority, as measured by antibody responses, of a 2-dose immunization schedule (0, 6 months) of recombinant human papillomavirus virus-like particle vaccine (type 16 and 18 L1 proteins, yeast) (hereinafter referred as HPV-2 vaccine) in adolescent females aged 9 to 14 years in comparison to 3-dose immunization schedule (0, 2, 6 months) in young females aged 18 to 26 years.