Pegylated interferon-alfa-2a is modified form of interferon with a 40 kDa polyethylene glycol strand attached to a recombinant interferon. This formulation increases the product's half-life from 7-10 hours to 77 hours. Therefore it can be administered on a more convenient once weekly basis. Pegylated interferon-alfa-2a monotherapy for 24 weeks has been shown to induce sustained HBeAg seroconversion in 35% of patients at the optimal dose of 180 mcg weekly. This drug has been found to be more effective than conventional interferon-alfa in the treatment of chronic hepatitis B as well as chronic hepatitis C.