Department of Mathematics, Annamalai University (INDIA)

In the study of HIV infection the progression of the disease takes place with the passage of time. This is due to the increasing the antigenic diversity level of the Retrovirus. As and when the total antigenic diversity crosses a threshold level, the sero conversion takes place. The threshold itself is considered to be a random variable. In this paper assuming that the antigenic diversity threshold satisfies the property known as Setting the Clock Back to Zero (SCBZ) property, the
expected time to sero conversion and its variance are derived. The results are augumented with suitable numerical illustrations.