HBeAg is a marker of active HBV replication in the liver indicating a highly infectious state. It appears within 1 week after appearance of HBsAg and is found only when HBsAg is present. HBeAg appears early in disease before biochemical changes and disappears after liver enzymes peak which is usually after 3-6 weeks. Persistence for more than 20 weeks suggests progression to Chronic carrier state and possible Chronic Hepatitis. It is the best predictor of maternal infectivity ( 90%) to untreated neonates at the time of delivery.