Immunogenicity and safety of an

Background: Vaccination with prophylactic human papillomavirus (HPV) vaccines is one of the most effective measures to prevent cervical cancer and other related diseases. Here we aimed to evaluate the immunogenicity and safety of an Method: We did a single-center, randomized, observer-blinded, positive controlled phase 2 clinical trial in healthy women aged 20-45 years. All eligible participants were randomly assigned (1:1:1) to receive 270 ug 9vHPV, 360 ug 9vHPV, or the control vaccine (Gardasil) with a 0-2-6-month schedule. Serum samples were collected at day 0 and month 7 to assess IgG and neutralizing antibodies (nAbs). For HPV 6/HPV 11/HPV 16/HPV 18, non-inferiority was identified for the lower limit of the 95% CI of the geometric mean titer (GMT) ratio at a margin of 0.5 and a seroconversion rate (SCR) difference at a margin of -5%. For HPV 31/HPV 33/HPV 45/HPV 52/HPV 58, superiority was demonstrated if the lower limit of the 95% CI for GMT ratio is greater than 1. Results: A total of 780 participants aged 20-45 years were enrolled, among whom 770 completed the three-dose immunization schedule. The incidences of ARs within 7 days in the 270 μg, 360 μg, and positive control groups were 38.85%, 41.92%, and 22.69%, respectively ( Conclusion: The candidate 9vHPV vaccine was well tolerated and immunogenic, supporting further evaluation for efficacy and safety in larger populations. Clinical Trial Registration: https://clinicaltrials.gov, identifier NCT05694728.