Single dose-inactivated hepatitis A vaccination schedule for susceptible youngsters

• Published in: The American journal of gastroenterology Vol. 91; no. 7; p. 1360
• Main Authors: Lee, S D, Chan, C Y, Yu, M I, Wang, Y J, Lo, K J, Safary, A
• Format: Journal Article
• Language: English
• Published: United States 01.07.1996
• Subjects: Adolescent; Child; Disease Susceptibility; Dose-Response Relationship, Immunologic; Drug Evaluation; Female; Hepatitis A - immunology; Hepatitis A - prevention & control; Hepatitis A Vaccines; Hepatitis A Virus, Human - immunology; Hepatitis Antibodies - blood; Humans; Immunization Schedule; Male; Taiwan; Time Factors; Vaccines, Inactivated - administration & dosage; Vaccines, Inactivated - adverse effects; Vaccines, Inactivated - immunology; Viral Hepatitis Vaccines - administration & dosage; Viral Hepatitis Vaccines - adverse effects; Viral Hepatitis Vaccines - immunology; Taiwan
• ISSN: 0002-9270; 1572-0241

To investigate the feasibility of a single-dose primary hepatitis A vaccination for young travelers. One hundred and nineteen susceptible youngsters, 9-18 yr old, received a dose of 720 ELISA units of the inactivated hepatitis A vaccine at month 0, and then a booster at month 6. Antibodies to hepatitis A virus (anti-HAV) seroconversion ( > or = 20 mIU/ml) in these vaccinees was 91% (106/117) on day 15, and reached 99% (118/119) 1 month after the single-dose vaccination. At month 6 before the booster, 97% (110/113) of the vaccinees still had detectable anti-HAV. All vaccinees (113/113) had measurable titers of anti-HAV 1 month after booster vaccination, and were still seropositive (68/68) at month 12. The anti-HAV response was found to be slower in vaccinees positive for hepatitis B surface antigen (11/16, 68.8%), compared with noncarrier vaccinees (95/101, 94.1%; p < 0.01) 15 days after the priming dose. After initial vaccination, the geometric mean titers of anti-HAV among vaccine responders were 220, 255, 117, 3308, and 1094 mIU/ml at day 15 and months 1, 6, 7, and 12, respectively. These results suggest that a single dose of hepatitis A vaccine could be a good alternative to immune serum globulin administration for immunoprophylaxis in young healthy travelers.