Zhou K, et al. - Via searching PubMed and Embase for observational cohort studies and non-treatment arms of randomised controlled trials, researchers systematically determined a pooled annual rate of HBsAg loss in adults with untreated chronic hepatitis B virus (HBV) infection and studied the impact of regional endemicity. Of 5186 studies screened, 67 met the inclusion criteria and 56 were involved in meta-analyses after exclusion of randomised controlled trials. It was noted that the pooled annual incidence of HBsAg loss was 1·17%. In treatment-naive adults with chronic HBV infection, globally, spontaneous HBsAg loss occurs infrequently (about 1% per year). The low and homogeneous rate of HBsAg loss underlines the need for new therapeutics to achieve functional cure across different patient groups and geographical regions. Data reported that HBV endemicity did not affect rates of HBsAg loss.