Single dose-inactivated hepatitis A vaccination schedule for susceptible youngsters.
OBJECTIVE
To investigate the feasibility of a single-dose primary hepatitis A vaccination for young travelers.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Lee
S D
SD
Department of Medicine, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Chan
C Y
CY
Yu
M I
MI
Wang
Y J
YJ
Lo
K J
KJ
Safary
A
A
D000293:Adolescent; D002648:Child; D004198:Disease Susceptibility; D004306:Dose-Response Relationship, Immunologic; D004341:Drug Evaluation; D005260:Female; D006506:Hepatitis A / Q000276:immunology / Q000517:prevention & control*; D022362:Hepatitis A Vaccines; D017957:Hepatitis A Virus, Human / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000097:blood; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D013624:Taiwan; D013997:Time Factors; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology
D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies; D015164:Vaccines, Inactivated; D014761:Viral Hepatitis Vaccines