A phase IV, randomization, single center, controlled clinical trial to compare the safety, immunogenicity,three-year immune persistence of inactivated hepatitis A vaccine (HAV) with one- or two-dose regimen and live attenuated HAV with one-dose regimen in Chinese young adults, and to evaluate the immunogenicity of a booster dose.

Healthy undergraduate students aged 16 to 25 years with anti-HAV negative were randomly divided into three groups. Group A and B were administrated with one-dose inactivated and live attenuated hepatitis A vaccines respectively; Group C was immunized with two doses of an inactivated vaccine with 6 months apart. Blood samples were collected at month 1, and 12, 24 and 36 for anti-HAV titers determination. Safety observation in 30 minutes' duration after vaccinations and injection-site reactions and systemic reactions for three consecutive days were recorded to assess the safety of investigational vaccines. At Month 36, subjects who received one dose of inactivated or live attenuated HAV were administrated a booster dose and then were taken blood samples one month later for anti-HAV titers determination.

Inclusion Criteria:

• Healthy undergraduate students aged 16 to 25 years
• Sign the informed consent
• Provide ID

Exclusion Criteria:

• Axillary temperature > 37.0 centigrade at the time of dosing
• Subject that has a medical history of any of the following: allergic history, or allergic to any ingredient of vaccine
• Serious adverse reactions to vaccines such as anaphylaxis, hives, respiratory difficulty, angioedema, or abdominal pain
• Autoimmune disease or immunodeficiency
• Congenital malformation, developmental disorders or serious chronic diseases (such as Down's syndrome, diabetes, sickle cell anemia or neurological disorders)
• Bleeding disorder diagnosed by a doctor (e.g. factor deficiency, coagulopathy, or platelet disorder requiring special precautions) or significant bruising or bleeding difficulties with IM injections or blood draws
• History or family history of convulsions, epilepsy, brain disease and psychiatric
• History of any blood products within 3 months
• Administration of any other investigational research agents within 30 days
• Administration of any live attenuated vaccine within 30 days
• Administration of subunit or inactivated vaccines within 14 days
• Any medical, psychiatric, social condition, occupational reason or other responsibility that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a volunteer's ability to give informed consent
• anti-HBsAg positive
• anti-HAV positive
• Pregnancy test result is positive