Impact of hepatitis B vaccine inoculation on prevalence of hepatitis B among 1 – 29 years old population in Tianjin city

  Objective  To compare changes in prevalence of viral hepatitis B (HB) and HB virus infection/immunization among 1 – 29 years old population before and after the inoculation of HB vaccine in Tianjin city and evaluate the outcome of HB prevention and control.

  Methods  We collected data on reported HB cases among residents in Tianjin city from 2007 to 2017 through Infectious Disease Report Information Management System and demographic data of same period from Tianjin Municipal Statistics Bureau. We also conducted a questionnaire survey and blood detection among 585 residents aged 1 – 29 years with random sampling. Serum HB virus surface antigen (HBsAg), antibody to HBsAg (anti-HBs), HB virus e antigen (HBeAg), antibody to HBeAg (anti-HBe), and antibody to HB core antigen (anti-HBc) were detected with enzyme-linked immunosorbent assay (ELISA). Descriptive statistics was adopted in data analyses.

  Results  During the period from 2007 to 2017 in the city, the mean incidence rate of acute HB was 1.47/100 000 among the population aged 1 – 29 years, significantly lower than that (2.07/100 000) among those aged ≥ 30 years (χ² = 150.957, P < 0.001). The incidence rate of HB was significantly higher among the male population than among the female population (P < 0.001). No HBsAg positive individuals were detected among the population less than 24 years old. The positive rate of anti-HBs was significantly higher among the children aged 1 – 4 years than that among those aged 5 – 14 years (χ² = 12.869) and 15 – 29 years (χ² = 6.179) (both P < 0.05). The predicted anti-HBs positive rate is 95.99% among the neonates having full-dose vaccination of HB vaccine. The results of logistic regression analysis indicated that HB vaccine inoculation and at younger age were strongly associated with anti-HBs positive (P < 0.05).

  Conclusion  Viral HB epidemic is well under control after the implementation of HB vaccine vaccination among general population in Tianjin city. The positive rate of serum anti-HBs is high among the neonates receiving full-dose HB vaccine inoculation and the HB virus infection rate and HB incidence rate do not increase among the neonates when their anti-HBs positive rate decreases with increment of age.