Seroprotection of Hepatitis B Vaccine and Need for Booster Dose: A Meta-Analysis

The duration of protection provided by hepatitis b (hb) vaccine is still unknown but can be estimatedindirectly by measuring the anamnestic immune response to booster doses of the vaccine.methods: we searched electronic databases and conference databases up to december 2008. we also screened referencelists of articles and contacted the authors and vaccine manufacturers for additional references. we included randomizedand nonrandomized studies assessing the anamnestic immune response to the booster of hb vaccine in healthy participants5 years or more after initial vaccination.results: the meta-analysis included 34 studies with 53 intervention groups and 4,479 individuals. the protective antibodiesinduced by initial vaccination waned over time; however, nonprotected vaccinees who had lost their antibodiesto hepatitis b surface antigen (anti-hbs) over time responded strongly to the booster dose. the seroprotection rate ofhb vaccine after the primary vaccination was 98.00% [95% confidence interval (ci): 95.32%, 99.52%] after 5 years,96.88% [95% ci: 94.61%, 98.50%] after 6-10 years, 88.80% [95% ci: 79.84%, 95.08%] after 11-15 years, and85.12% [95% ci: 82.18%, 88.20%] after 16-20 years.conclusions: according to these findings, the protection provided by hb vaccine is dependent on immune memory ratherthan anti-hbs titer; therefore, recommendations for booster doses should be based on immune memory instead of thepersistence of antibody. in addition, a full course of hb vaccination can induce a long-term and strong serologic immunityagainst hepatitis b virus infection. nonetheless, the decreasing trend of seroprotection during the first and seconddecades after immunization indicates that the long-term immunity induced by hb vaccine may diminish over time. thisissue raises the possibility of the need for a booster dose, although universal revaccination does not seem necessaryduring the first and second decades after primary vaccination in healthy individuals with normal immune status who hadfully responded to a complete course of the vaccine.