Optimal control of HIV infection with a continuously-mutating viral population

There has been much discussion in recent years devoted to determining the optimal methodology for administering anti-viral medication therapies to fight HIV infection. There are many reasons to seek such an optimal therapy, including the minimization of drug toxicity and monetary cost. However, there is increasing recognition that exposure to many anti-HIV medications produces extremely rapid changes in the viral population in an infected individual, from drug-sensitive to drug-insensitive viral strains. This paper investigates the reasons underlying the development of drug-insensitive HIV strains, and then, using numerical optimal control techniques, demonstrates that optimal drug administration may be useful in increasing patient health by delaying the emergence of drug-resistant mutant viral strains.