Safety and immunogenicity of an

A safe and highly efficacious Escherichia coli (E. coli)-produced HPV 16/18 bivalent vaccine has been prequalified by the World Health Organization. Here, we conducted a single-center, open-label, dose-escalation phase 1 clinical trial to evaluate the safety and immunogenicity of the second-generation nonavalent HPV 6/11/16/18/31/33/45/52/58 vaccine.

Twenty-four eligible volunteers aged 18-45 years were enrolled in January 2019 in Dongtai, China and received 0.5 mL (135 μg) or 1.0 mL (270 μg) of the candidate vaccine with a 0/1/6-month dose-escalation schedule. Local and systemic adverse events (AEs) occurring within 30 days after each vaccination and serious adverse events (SAEs) occurring within 7 months were recorded. Blood samples from each participant were collected before and 2 days after the first and third vaccinations to determine changes in laboratory parameters. Serum IgG and neutralizing antibody (nAb) levels against each HPV type at month 7 were analyzed (ClinicalTrials.gov: NCT03813940).

The incidences of total AEs in the 135 μg and 270 μg groups were 66.7% and 83.3%, respectively. All AEs were mild or moderate, and no SAEs were reported. No clinically significant changes were found in paired blood indices before or after any of the vaccinations. All the participants in the per-protocol set except for two who failed to seroconvert for HPV 11 or 58 in the 135 μg group seroconverted at month 7 for both IgG and nAbs.

The candidate E. coli-produced 9vHPV vaccine has been preliminarily proven to be well tolerated and immunogenic, which encourages further studies in large cohorts with a wider age range.

This study was supported by the National Natural Science Foundation of China, Fujian Provincial Natural Science Foundation, Fujian Province Health and Education Joint Research Program, Xiamen Science and Technology Plan Project, Fundamental Research Funds for the Central Universities, CAMS Innovation Fund for Medical Sciences of China, and Xiamen Innovax Biotechnology Co., Ltd.