Hepatitis B ; immunology ; prevention & control ; Hepatitis B Vaccines ; immunology

Hepatitis B ; immunology ; prevention & control ; Hepatitis B Vaccines ; immunology ; Humans ; Immunization Schedule ; Vaccination ; Vaccines, Synthetic ; immunology

Hepatitis E ; immunology ; prevention & control ; Humans ; Viral Hepatitis Vaccines

Hepatitis E ; etiology ; prevention & control ; Hepatitis E virus ; immunology ; Humans ; Viral Hepatitis Vaccines ; immunology

One of the major cause of recent acute viral hepatitis in Korean adults is hepatitis A virus (HAV) infection. Most of hepatitis A cases are young adults in their twenties or thirties, and the severity of the disease is related to the age of patients. The seroprevalence of HAV among the adolescents and young adults in their teens and twenties is about 10%, which suggests that a growing number of young adults are susceptible to HAV infection. Development of more adult cases with severe presentation is expected in the near future, and some preliminary data suggest the incidence rate of hepatitis A in Korea might be higher than 20/100,000 population. This clinical features and the epidemiological shift of HAV urge to promote childhood vaccination and consider catch-up vaccination for adolescents and young adults. More extensive evaluation on the nationwide epidemiology of HAV infection, cost-benefit analysis of HAV vaccination, and setting-up of guidelines for HAV vaccination are urgently warranted.
Adolescent ; Adult ; Child ; Hepatitis A/immunology/*prevention & control ; Hepatitis A Antibodies/immunology ; *Hepatitis A Vaccines ; Humans ; Immunization Schedule ; Korea ; Seroepidemiologic Studies ; Vaccines, Inactivated

OBJECTIVETo evaluate safety and immunogenicity of inactivated hepatitis A vaccine in HBsAg carriers and healthy children.

METHODSOne hundred and twenty-one healthy children and ten HBsAg carriers, aged 1-10 years HAV susceptible were enrolled in the study. The inactivated hepatitis A vaccine was produced by Tangshan Biogenetic Company. The dosage of the vaccine was 1000 U/Dosage and 500 U/Dosage. The vaccination schedule was six month apart for two injections. The serum anti-HAV level was detected with EIA at one month after first injection and at one and six month after the booster injection, respectively.

RESULTSThe anti-HAV appeared in all the children. One month after the booster injection, the serum anti-HAV level in children vaccinated 500 U/Dosage was 4684.9 mIU and 4535.6 mIU, respectively and in the children vaccinated 1000 U/Dosage, 5399.8 mIU and 7347.1 mIU, respectively. The anti-HAV level was not statistically different between the two groups of children. There was no adverse reaction after the vaccination. The anti-HAV level was still high one year after first injection.

CONCLUSIONSThe data indicated that the safety and immunogenicity of the domestic inactivated hepatitis A vaccine were excellent in both groups of children.

Child ; Child, Preschool ; Hepatitis A Antibodies ; blood ; Hepatitis A Vaccines ; immunology ; Hepatitis B Surface Antigens ; blood ; Humans ; Immunization ; Infant ; Vaccines, Inactivated ; immunology

OBJECTIVETo evaluate the immunogenicity, safety, and dosage of a new inactivated hepatitis A vaccine administered to young adults.

METHODSOne hundred and four normal adult volunteers, seronegative for hepatitis A virus and hepatitis B surface antigen, were randomly assigned to one of three groups. The high-dose group received a primary dose of 1000 units of the new vaccine, the low-dose group received a primary dose of 500 units of the same vaccine, and the Havrix group received a primary dose of 1440 enzyme-linked immunosorbent assay units of Havrix, a licensed inactivated hepatitis A vaccine. All groups received a booster dose of the same vaccine 6 months after the primary dose. Local and systemic adverse reactions, seroconversion rates, and geometric mean titers of hepatitis A virus antibodies were measured in all three groups.

RESULTSLocal and systemic reaction types and rates were similar in all three groups after primary and booster doses, although local reactions were more frequent in the Havrix group following the primary dose. No serious adverse reactions occurred. One month after the primary dose, the seroconversion rate was 87.5% in the high-dose group, 70.0% in the low-dose group, and 50.0% in the Havrix group (P = 0.001, versus the high-dose group). At month 6 (before administration of the booster dose), seroconversion rates were 96.9% in the high-dose group, 65.0% in the low-dose group (P = 0.0029), and 68.8% in the Havrix group (P = 0.007). All subjects in all groups seroconverted by one month after receipt of the booster dose. Geometric mean titers were similar in all three groups at month 1, but were higher in the high-dose group (264 mIU/ml) than those in the Havrix group (135 mIU/ml) at month 6 (P = 0.0013). One month after the booster dose, geometric mean titers in the high-dose group (2747 mIU/ml) were higher than those in the low-dose group (1657 mIU/ml) (P = 0.0223) or in the Havrix group (1316 mIU/ml) (P = 0.01).

CONCLUSIONSThis new inactivated hepatitis A vaccine is immunogenic and safe; two doses of either 500 or 1000 units can induce hepatitis A virus antibodies well above the protection level.

Adolescent ; Adult ; Hepatitis A Vaccines ; adverse effects ; immunology ; Humans ; Vaccines, Attenuated ; adverse effects ; immunology

OBJECTIVETo observe the immunogenicity of combined hepatitis A and B vaccine (HAB).

METHODSThe combined HAB vaccine was prepared and different concentrations of HAB were administered on mice in week 0, 4 and 24, and then we tested the antibodies to both hepatitis A virus and B virus. After the first injection, we tested the hepatitis A antigen-induced and hepatitis B surface antigen-induced stimulation indices in spleen monocyte as well as changes of CD4+ and CD8+ cell numbers.

RESULTSThe serum antibody positive rates were 100% in all three groups, and the antibody induced by HAB vaccine were earlier than by monovalent vaccine. The hepatitis A antibody and hepatitis B surface antibody titers after the combined vaccine inoculation were not significantly higher than those after the monovalent vaccine inoculation. On the other hand, after the first injection of the combined vaccine, the hepatitis A antigen-induced and hepatitis B surface antigen-induced stimulation indices in spleen monocyte were detected. The numbers of CD4+ and CD8+ cells increased.

CONCLUSIONSHAB vaccine has reliable immunogenicity.

Animals ; CD4-CD8 Ratio ; Hepatitis A ; prevention & control ; Hepatitis A Antibodies ; blood ; Hepatitis A Vaccines ; immunology ; Hepatitis B ; prevention & control ; Hepatitis B Antibodies ; blood ; Hepatitis B Vaccines ; immunology ; Leukocytes, Mononuclear ; immunology ; Mice ; Mice, Inbred BALB C ; Random Allocation ; Vaccination ; Vaccines, Combined ; immunology

Animals ; Hepacivirus ; genetics ; Hepatitis C ; immunology ; prevention & control ; therapy ; virology ; Humans ; Mutation ; Viral Hepatitis Vaccines ; immunology

Adolescent ; Child ; Female ; Hepatitis B Antibodies ; blood ; Hepatitis B Vaccines ; immunology ; Humans ; Male ; Thymosin ; therapeutic use ; Vaccination ; Vaccines, Synthetic ; immunology