Zhao YL, Meng ZD, Xu ZY, Guo JJ, Chai SA, Duo CG, Wang XY, Yao JF, Liu HB, Qi SX, Zhu HB. H2 strain attenuated live hepatitis A vaccines: Protective efficacy in a hepatitis A outbreak. World J Gastroenterol 2000; 6(6): 829-832 [PMID: 11819704 DOI: 10.3748/wjg.v6.i6.829]
Corresponding Author of This Article
Dr. Yu Liang Zhao, Department of Virology, Hebei Provincial Sanitary and Anti-epidemic Station, 36 Hongqi Road, Baoding 071000, Hebei Province, China. Email: yuliang_zh@hotmail.com
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World J Gastroenterol. Dec 15, 2000; 6(6): 829-832 Published online Dec 15, 2000. doi: 10.3748/wjg.v6.i6.829
H2 strain attenuated live hepatitis A vaccines: Protective efficacy in a hepatitis A outbreak
Yu Liang Zhao, Zong Da Meng, Zhi Yi Xu, Jun Jie Guo, Shao Ai Chai, Cheng Gang Duo, Xuan Yi Wang, Jin Feng Yao, Hong Bin Liu, Shun Xiang Qi, Hui Bin Zhu
Yu Liang Zhao, Zong Da Meng, Hong Bin Liu, Department of Virology, Hebei Provincial Sanitary and Anti-epidemic Station, Baoding 071000, Hebei Province, China
Yu Liang Zhao, Zhi Yi Xu, Xuan Yi Wang, Shun Xiang Qi, Department of Epidemiology, Shanghai Medical University, Shanghai 200032, China
Jun Jie Guo, Cheng Gang Duo, Jin Feng Yao, Fucheng County Sanitary and Anti-epidemic Station, Baoding 071000, Hebei Province, China
Shao Ai Chai, Hui Bin Zhu, Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang Province, China
Yu Liang Zhao, graduated from Hebei Medical University as a postgraduate in 1990, is now an associate chief doctor majoring in hepatic epidemiology and a Ph.D student in Shanghai Medical University. He had 31 papers published and was the chief editor of theoretical epidemiology of infectious diseases.
Author contributions: All authors contributed equally to the work.
Supported by national ninth five-year study program for tackling key scientific problems, No.03-01-01
Correspondence to: Dr. Yu Liang Zhao, Department of Virology, Hebei Provincial Sanitary and Anti-epidemic Station, 36 Hongqi Road, Baoding 071000, Hebei Province, China. Email: yuliang_zh@hotmail.com
Received: June 28, 2000 Revised: July 12, 2000 Accepted: July 16, 2000 Published online: December 15, 2000
Abstract
AIM: To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) out breaks.
METHODS: With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (106.5TCID50) of H2-strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997. Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.
RESULTS: HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 d. Overall 302 HA cases were found, 192 (63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95%CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1 (0.40%) overt and 11 (4.06%) asymptomatic HAV cases were found in 271 vaccinees，but 21 (6.69%) of overt and asymptomatic ones were found in 314 controls.
CONCLUSION: H2 strain vaccines were excellent in preventing overt hepatitis A, but not so effective in preventing asymptomatic hepatitis A virus infection. A booster dose might be needed to get permanent reliable immunity.
