A Phase Ⅳ Clinical Trial of the Recombinant Hepatitis E Vaccine (Escherichia Coli)

Inclusion Criteria: 1. Healthy people aged over 18 years old on the day of enrollment 2. Axillary temperature is below than 37.0 ℃ 3. Blood pressure is not higher than 160/100 mmHg (with or without any medicine) 4. Judged as healthy and eligible for vaccination by the investigators through a self-reported medical history and some physical examinations. 5. Able to understand this study information and willing to comply with all study requirements. 6. Willing to participate in this study and sign informed consent form. Exclusion Criteria: 1. Participated in any other clinical trial during the study period. 2. Use of any investigational product or non-registered product (drug or vaccine) within 30 days preceding the first dose of the study vaccine or plan to use during the study period. 3. Received immunosuppressed, immunoregulation therapy or corticosteroid systemic therapy for more than 14 days in the 6 months before entry, except local treatment. 4. Administration of any immunoglobulin or blood products within 3 months preceding the first dose of the study vaccine,or plan to use during the study period. 5. Administration of any inactivated vaccines within 14 days preceding the first dose of the study or attenuated live vaccines within 21 days preceding the first dose of the study. 6. Had a fever (axillary temperature over 38°C) within 3 days or acute illness requiring systemic antibiotics or antiviral treatment within 5 days before vaccination. 7. Immunodeficiency (such as HIV carriers), primary disease of important organs, malignant tumor, .or any immune disease (such as systemic lupus erythematosus, arthritis pauperum, splenectomy or functional asplenia or other disease which might affect immune response). 8. History of allergic disease or history of serious adverse events occurring after vaccination, i.e., allergy,urticaria, dyspnea, angioneurotic edema or abdominal pain. 9. Pregnant or breastfeeding 10. Allergic history to any component of this vaccine. 11. Other medical, psychological, social or occupational factors that, according to the investigators' judgment,might affect the individual's ability to obey the protocol or sign the informed consent.