The purpose of this study is to determine the safety and immunogenicity of the recombinant hepatitis E vaccine in people older than 65 years, and evaluate the efficacy of hepatitis E vaccine in this population.

Inclusion Criteria:

• Healthy people aged over 16 years old at the time of the first vaccination, normal intelligence and agree to sign the informed consent form.
• Healthy subjects as established by medical history and history-oriented clinical examination before entering into the study.
• Subjects will reside in the study region in the next 7 months.
• Free of history of hepatitis E.
• Can comply with the request of study.
• Axillary temperature is below 37 degree centigrade.

Exclusion Criteria:

For dose 1:

• receiving other vaccine or immunoglobulin within two weeks;
• Having serious allergic history to vaccine and medicine
• Eclampsia, epilepsy, encephalopathy and history of mental disease or family;
• Thrombocytopenia or other disturbance of blood coagulation which would lead to muscle injection taboo;
• Fixed or suspected deficiency of immunologic function, containing immunosuppressant treatment, genetic defect, HIV or other factors;
• Congenital malformation, eccyliosis or severe chronic disease;
• Fixed or suspected other disease including fever, active infection, liver and kidney disease, angiocardiopathy, malignancy, acute and chronic disease;
• joining other clinical study undergoing;
• women pregnant or in lactation.

For dose 2 or 3:

• Severe allergy for dose 1 or 2;
• Severe adverse reaction associated with last vaccination;
• New occurrence of symptoms meet dose 1 exclusion criteria after the first dose.