Plots of viral levels against time under different immune response models. Neutralizing antibodies are not very efficient in controlling viral levels. The antibody response model yielded levels that settled to levels comparable to those of the basic model (model without immune system intervention). Lowest viral levels are obtained when all the specific immune system components work simultaneously as is shown by the graph of the combined model. Killing of infected cells also play a very crucial role in reducing the viral levels as can be seen from the graph of the lytic model. The parameter values used are given in Table 1 and the initial conditions were .