[Effectiveness of post-exposure prophylaxis using live attenuated hepatitis Alpha vaccine (H(2) strain) among schoolchildren].
OBJECTIVE
To observe the efficacy of emergency immunization to abort hepatitis Alpha outbreak using live attenuated hepatitis Alpha vaccine.


METHODS
During an outbreak of hepatitis Alpha in a village in Zhengding County, Hebei Province, one dose of live attenuated hepatitis Alpha vaccine (H(2) strain) was administered to 92 schoolchildren of two primary schools in that village on a voluntary basis, and 189 schoolchildren who were not vaccinated were used as controls. Their serum specimens were collected 3 times at different time points (0 and 18 days after the vaccination and 40 days after the appearance of the last hepatitis Alpha case). The total antibody and IgM of hepatitis Alpha were examined by ELISA. Clinical observation was made to discover whether new case appeared. The rates of seroconversion and hepatitis Alpha in susceptibles between vaccinated and unvaccinated groups were compared.


RESULTS
The new infection rate of hepatitis Alpha during the 18 days after vaccination was 5.43% in the vaccinated group and 7.43% in the control group (P > 0.05). The prevalence rate was 0 in both groups (P > 0.05). The new infection rate of hepatitis Alpha during the period from the 18th day after vaccination to the 40th day after the appearance of the last case was 2.41% in the vaccinated group and 3.21% in the control group (P > 0.05).


CONCLUSIONS
The live attenuated hepatitis Alpha vaccine can not provide post-exposure protection against infection of hepatitis Alpha virus during the outbreak.
Wang
Xuanyi
X
Department of Molecular Virology, School of Medicine, Fudan University, Shanghai 200032, China.
Ma
Jingchen
J
Xu
Zhiyi
Z
Liu
Hongbin
H
Zhang
Yinglin
Y
Han
Changquan
C
D002648:Child; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology / Q000517:prevention & control*; D022362:Hepatitis A Vaccines / Q000276:immunology*; D006801:Humans; D008297:Male; D014613:Vaccines, Attenuated / Q000276:immunology
D022362:Hepatitis A Vaccines; D014613:Vaccines, Attenuated