The study on immune effectiveness of people vaccinated by Hepatitis B recombinant yeast-derived vaccine for 6-9 years

Objective To valuate the immune effectiveness of hepatitis B recombinant yeast-derived vaccine after universal vaccination in newborns for a long time.Methods Cohort study combined with cross-sectional seroepidemiological survey was carried out to investigate the people who had been vaccinated with hepatitis B recombinant yeast-derived vaccine just while they were born in 1996,1997,1998 and 1999.The blood samples of them were taken and the infective markers of hepatitis B virus were tested by SPRIA.The results were analyzed and compared with history data.Results(1) Average HBsAg positive rate was 1.9%(95%CI 1.4%～2.4%),protective anti HBs rate was 53.2%(95%CI 51.2%～55.2%);the difference of two mapkers between female and male had no statistic significance.(2) The level of four cohorts showed decenttrend by the time.The protective anti HBs rate dropped from 88.2%(1 year after vaccination) to 44.3%(9 year after vaccination).The positive rates of HBsAg among 4 cohorts had no statistic significance.(3) The average protective rate of vaccination was 89.9% and had no statistic difference to data of 2000.Conclusion Most of newborns vaccinated by hepatitis B vaccine can prevent the infection from hepatitis B virus.Although the protective anti HBs of vaccinated people shows decent trend by the time,the protective result of vaccine is still stable.