论文通过详实的数据，证实我校自主研发的世界上第一个戊型肝炎疫苗能够使接种者产生良好的持久免疫力，显著降低罹患戊型肝炎的风险。在同期刊发的题为《使戊型肝炎成为‘疫苗可预防的疾病’》的评论中，美国疾病预防控制中心Eyasu　Teshale博士认为“戊肝疫苗可以成为预防控制戊肝疾病和传播的新工具”，并提出“基于该研究给出的戊肝疫苗持久保护证据，现在已到了实现戊肝疫苗的公共卫生应用的时候”。 ; BACKGROUND Hepatitis E virus (HEV) is a leading cause of acute hepatitis. The long-term efficacy of a hepatitis E vaccine needs to be determined. METHODS In an initial efficacy study, we randomly assigned healthy adults 16 to 65 years of age to receive three doses of either a hepatitis E vaccine (vaccine group; 56,302 participants) or a hepatitis B vaccine (control group; 56,302 participants). The vaccines were administered at 0, 1, and 6 months, and the participants were followed for 19 months. In this extended follow-up study, the treatment assignments of all participants remained double-blinded, and follow-up assessments of efficacy, immunogenicity, and safety were continued for up to 4.5 years. RESULTS During the 4.5-year study period, 60 cases of hepatitis E were identified; 7 cases were confirmed in the vaccine group (0.3 cases per 10,000 person-years), and 53 cases in the control group (2.1 cases per 10,000 person-years), representing a vaccine efficacy of 86.8% (95% confidence interval, 71 to 94) in the modified intention-to-treat analysis. Of the participants who were assessed for immunogenicity and were seronegative at baseline, 87% of those who received three doses of the hepatitis E vaccine maintained antibodies against HEV for at least 4.5 years; HEV antibody titers developed in 9% in the control group. The rate of adverse events was similar in the two groups. CONCLUSIONS Immunization with this hepatitis E vaccine induced antibodies against HEV and provided protection against hepatitis E for up to 4.5 years. ; Supported by grants from the Chinese Ministry of Science and Technology National Major Scientific and Technological Special Project for “Significant New Drugs Development” (2013ZX09101017), National Natural Science Foundation of China (81373061), National High-Tech Research and Development Program (863 Program) (2012AA02A408), and Jiangsu Science and Technology Support Program (BE2013723).