Immunogenicity and safety of hepatitis E vaccine in healthy hepatitis B surface antigen positive adults.

A recombinant hepatitis E vaccine, Hecolin, has been proven safe and effective in healthy adults. As hepatitis B surface antigen (HBsAg) positive individuals have a higher risk of poor prognosis after super-infection with hepatitis E virus (HEV), the safety and immunogenicity of Hecolin in this population should be assessed. The present study is an extending analysis of data from a large randomized controlled clinical trial of Hecolin. Healthy participants (n = 14,065) without current or previous evidence of chronic liver disease were randomized to receive Hecolin or placebo (hepatitis B vaccine) and donated their blood samples before vaccination and subsequently over 31 mo. Most of the adverse events were mild and comparable between participants with and without baseline hepatitis B surface antigen (HBsAg). No vaccine-related serious adverse events were reported. Rates of serious adverse events in HBsAg (+) or HBsAg (-) participants were also comparable between both groups. Almost all participants in the Hecolin group seroconverted to anti-HEV one month after full vaccination. The antibody response rates and levels were similar in HBsAg (+) and HBsAg (-) participants (98.38%, 19.32 Wu/mL vs. 98.69%, 19.00 Wu/mL). The two-year antibody dynamics of HBsAg (+) participants overlapped perfectly with those of HBsAg (-) participants. In conclusion, the safety and immunogenicity of Hecolin for HBsAg (+) adults is very similar to that for the general population.