Long‐Term Immunity and Anamnestic Response Following Hepatitis B Vaccination: A Systematic Review and Meta‐Analysis

Using a systematic review and meta-analytic approach, this study determined the durability of HBV immunity and the prevalence of anamnestic response to a booster HBV vaccine dose in individuals previously vaccinated with a 3-dose HBV vaccine series as children or adolescents. Two researchers independently searched PubMed, Embase and Cochrane from inception to 6/1/2023 and performed data extraction. Studies that included individuals with significant comorbidities or < 5 years of follow-up were excluded. Of 2517 potential studies, we analysed 91 eligible studies (193,359 individuals from 208 cohorts [some studies provided data for more than one cohort]). Median age at vaccination was 0 years (range: 0-20.00). After a median follow-up of 10.15 years (range: 5-35), 63.2% (95% CI: 59.3-67.0) retained HBV immunity. HBV immunity declined by 6.62% per follow-up year (Ptrend < 0.0001). In meta-regression adjusting for vaccine type, follow-up time and geographic location, age at vaccination was significantly associated with retaining HBV immunity (adjusted odds ratio [aOR] 1.12 per year, p < 0.0001). Anamnestic response rate (44 studies, 66 cohorts, 29,040 patients) was 90.34% (95% CI: 86.84-92.98), with highest rates in Europe and Asia, but only study setting (clinical versus community-based: aOR 2.21, p = 0.034) was an independent factor. HBV immunity prevalence was about 60% after 10 years following childhood vaccination. Anamnestic response rate was about 90% and varied by study setting. Testing for immunity should be considered in individuals with high exposure risk and distant vaccination history with booster as needed.