Estimation of Expected Time for Antigenic Diversity to Cross the Threshold in HIV Infection

Antigenic diversity is an important aspect in the progression of HIV infection. Several authors have studied the antigenic diversity in HIV infected. Nowak and May (1991) have studied the mathematical biology of HIV infection with particular reference to antigenic diversity. Nowak et al., (1991) have studied the impact of antigenic diversity threshold in the progression of AIDS. As and when the total antigenic diversity crosses the so called threshold level, the seroconversion takes place. The estimation of time to cross the antigenic diversity threshold is very useful in the prediction of the expected time to seroconversion. In this paper the expected time to seroconversion is estimated by using the shock model approach. The Shock model approach and cumulative damage process have been studied by Esary et al., (1973). In estimating the time for the antigenic diversity to cross the threshold, it is assumed that the threshold follows the first order statistic. Numerical illustration is also provided.