Safety and immunogenicity of a domestic recombinant hepatitis E vaccine in a 16-65 years old population

Objective To clinically evaluate the safety and immunogenicity of the recombinant hepatitis E vaccine developed by Changchun Biological Products Research Institute Company Limited in a population aged 16 to 65 years old. Methods We first selected subjects who were HEV antibody negative as a target population by screening. Then, a single center, randomized, blind trial with a similar product as a parallel control was conducted that sixty 16-65 years old healthy subjects who were HEV antibody negative were randomized to receive study vaccines or controlled vaccines by the ratio of 1:1. The immunization schedule consisted of 3 doses given on month 0, month 1 and month 6. Adverse reactions/events within 28 days after each dose were recorded. Hepatitis E IgG concentrations were detected with blood samples collected before immunization and 1 month after full schedule. Results We recruited 369 subjects. Among them, 187 were hepatitis E antibody negative after screening, and 60 subjects were enrolled in the trial eventually. Overall incidence of solicited adverse effects after 3 doses vaccination in the test group and the control group were 43.33% and 40.00% respectively. Majority of the adverse effects were mild and moderate. The most common injection-site and systemic reactions were pain and headache. The occurrence rates of adverse effects were not significantly different between groups (all P>0.05). Seropositive rates of HEV antibody after vaccination in the test group and the control group were both 100% and GMCs were 72.53 U/ml and 87.49 U/ml respectively. Conclusion The test vaccine has good safety and immunogenicity and a phase Ⅱ clinical trial can be carried out.