Objective: To evaluate the long-term efficacy of Chinese hamster ovary (CHO) cell derived hepatitis B vaccine after being used for 14-16 years in country community in Hebei province in China.
Method: A cross-sectional investigation was carried out in 3 of 7 randomly selected rural communities in Zhengding County in 2013. The children who were born between 1997 and 1999 and were vaccinated with three doses of CHO-derived hepatitis B vaccine were eligible to participate in the study. Their sera samples were tested for HBV serological markers. For HBsAg positive children, their historical results were compared, in order to see whether these were new infections.
Results: Among the 920 participating children, the prevalence of HBsAg, anti-HBs and anti-HBc were 0.65%, 73.15% and 1.20% respectively. The differences between birth-year groups were not significant. When compared with baseline, the vaccine efficacy was 94.2% and the anti-HBs titers of 668 children with sole anti-HBs positivity were 178.8 mI U/ml. By comparing with historical data, no new infection was found in this latest survey. Among 6 mothers of HBsAg positive children, 4 were HBsAg positive, 1 was negative and 1 was unknown.
Conclusion: The long-term efficacy of the CHO derived hepatitis vaccine is good and stable for 14-16 years after vaccination. A booster dose seems not necessary. Implementing mother-newborn blocking measures for newborns from HBsAg carrier mothers is urgently needed in the future.
Keywords: Children; Chinese hamster ovary cell; Hepatitis B vaccination; Hepatitis B virus; Long-term efficacy; Neonates.
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