A novel method of treating and preventing viral infection is provided. In
particular a method of blocking viral infection facilitated by a serine
proteolytic (SP) activity is disclosed, which consists of administering to
a subject suffering or about to suffer from viral infection a
therapeutically effective amount of a compound having a serine protease
inhibitory or serpin activity. Among compounds are .alpha..sub.1
-antitrypsin (AAT), peptide derivatives from the carboxyterminal end of
AAT, and man-made, synthetic compounds mimicking the action of such
compounds. The preferred viral infections include retroviral infection
such as human immunodeficiency virus (HIV) infection.
