Long-term follow-up of hepatitis A vaccination in children.
We conducted this follow-up study to evaluate the long-term immunogenicity of an inactivated hepatitis A vaccine in children. Ninety-six children who had seroconversion to antibody to HAV (anti-HAV) after receiving a three-dose schedule of inactivated hepatitis A vaccine were enrolled into this study. Sixty months after the initial vaccination, all vaccinees who received annual follow-up still had protective levels of anti-HAV. The geometric mean titer (GMT) of anti-HAV, peaking at month 7 (4133 mIU/mL), kept declining throughout the follow-up period. The GMTs in months 12, 24, 36, 48 and 60 were 1722, 896, 896, 645 and 403 mIU/mL, respectively. Nine of the vaccinees were hepatitis B virus carriers. Their anti-HAV titers tended to be lower than those of the remaining vaccinees at all time-points, but the difference was not significant (p > 0.05). Natural booster was noted in one vaccinee during the follow-up period. In conclusion, inactivated hepatitis A vaccine is safe and immunogenic in children, the duration of protection against HAV infection is longer than five years.
Chan
C Y
CY
Department of Medicine, Veterans General Hospital-Taipei, Taiwan, ROC.
Lee
S D
SD
Yu
M I
MI
Wang
Y J
YJ
Chang
F Y
FY
Lo
K J
KJ
D002648:Child; D005500:Follow-Up Studies; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D006507:Hepatovirus / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D013997:Time Factors; D014761:Viral Hepatitis Vaccines