Delay effect in a model for virus replication

As biology becomes more quantitative, it appears that the increasing use of mathematics in this area is inevitable. In 1996, Nowak & Bangham (1996, Sc ience 272, 74-79) proposed three mathematical models to explore the relatio n between antiviral immune responses, virus load, and virus diversity. In t his paper we investigate the delay effect in a model which considers the in teraction between a replicating virus and host cells. We assume that there is a finite time lag between infection of a cell and the emission of viral particles. Even with the introduction of this delay, the steady states of t he model-as suggested by Nowak Br Bangham-remain stable. The result also gi ves a condition for how the parameter values should be chosen when analysin g clinical data so that the model remains tenable.