Human immunodeficiency virus (HIV) comprising reverse transcriptase inactivated by photoinactivation. The inactivated virus may be more safely handled, stored, and analyzed, used in diagnostic procedures and kits, and may be used as an immunogen to evoke an immune response. The immune response may protect an individual from challenges with live virus. Alternatively, the inactivated HIV particles may be used to augment the immune response to HIV in an infected individual.