Abstract: In HIV infection the event of significance is the time at which the condition of AIDS begins to develop in an infected individual. Nowak and May (1991) suggested the existence of Antigenic Diversity Threshold (ADT) beyond which the immune system is unable to sustain against the viral populations. It is assumed that the condition of AIDS occurs on crossing this Antigenic Diversity Threshold (ADT). In this paper an attempt has been made to estimate the time to Cross Antigenic Diversity Threshold (CADT) under the assumption that frequent contacts with infected individual has an impact on the antigenic diversity and hence on the development of AIDS.

Keywords: Human Immunodeficiency Virus, Acquired Immuno Deficiency Virus, Antigenic Diversity Threshold.