Several assays show hepatitis B positivity soon after vaccination

Editor—The advent of the latest generation of assays for hepatitis B surface antigen (HBsAg) has been accompanied by a rise in the number of blood donors found to be positive for the antigen. Specific neutralisation has confirmed that these donors are HBsAg positive, but testing for antibody to hepatitis B core antigen (HBcAg) and for e antigen (HBeAg) and antibody has invariably proved fruitless. Such a serological pattern of reaction only to HBsAg is generally explained by a very early acute infection …