Forde, Jonathan E.Ciupe, Stanca M.Cintron-Arias, ArielLenhart, Suzanne2017-09-202017-09-202016-08-03Forde, J.E.; Ciupe, S.M.; Cintron-Arias, A.; Lenhart, S. Optimal Control of Drug Therapy in a Hepatitis B Model. Appl. Sci. 2016, 6, 219.http://hdl.handle.net/10919/79288Combination antiviral drug therapy improves the survival rates of patients chronically infected with hepatitis B virus by controlling viral replication and enhancing immune responses. Some of these drugs have side effects that make them unsuitable for long-term administration. To address the trade-off between the positive and negative effects of the combination therapy, we investigated an optimal control problem for a delay differential equation model of immune responses to hepatitis virus B infection. Our optimal control problem investigates the interplay between virological and immunomodulatory effects of therapy, the control of viremia and the administration of the minimal dosage over a short period of time. Our numerical results show that the high drug levels that induce immune modulation rather than suppression of virological factors are essential for the clearance of hepatitis B virus.application/pdfenCreative Commons Attribution 4.0 Internationaloptimal controlhepatitis Bdelay differential equations (DDE)immune responsedrug therapyArticle - Refereed2017-09-20https://doi.org/10.3390/app6080219