title: Chikungunya Virus: In Vitro Response to Combination Therapy With Ribavirin and Interferon Alfa 2a.
abstract: We evaluated the antiviral activities of ribavirin (RBV) and interferon (IFN) alfa as monotherapy and combination therapy against chikungunya virus (CHIKV).
  
  
  
  Vero cells were infected with CHIKV in the presence of RBV and/or IFN alfa, and viral production was quantified by plaque assay. A mathematical model was fit to the data to identify drug interactions for effect. We ran simulations using the best-fit model parameters to predict the antiviral activity associated with clinically relevant regimens of RBV and IFN alfa as combination therapy. The model predictions were validated using the hollow fiber infection model (HFIM) system.
  
  
  
  RBV and IFN alfa were effective against CHIKV as monotherapy at supraphysiological concentrations. However, RBV and IFN alfa were highly synergistic for antiviral effect when administered as combination therapy. Simulations with our mathematical model predicted that a standard clinical regimen of RBV plus IFN alfa would inhibit CHIKV burden by 2.5 log10 following 24 hours of treatment. In the HFIM system, RBV plus IFN alfa at clinical exposures resulted in a 2.1-log10 decrease in the CHIKV burden following 24 hours of therapy. These findings validate the prediction made by the mathematical model.
  
  
  
  These studies illustrate the promise of RBV plus IFN alfa as a potential therapeutic strategy for the treatment of CHIKV infections.
authors: Institute for Therapeutic Innovation, Department of Medicine, University of Florida, Orlando.
authors: Karen M
authors: KM
authors: Gallegos
authors: Institute for Therapeutic Innovation, Department of Medicine, University of Florida, Orlando.
authors: George L
authors: GL
authors: Drusano
authors: Department of Biomedical Engineering, University of Southern California, Los Angeles.
authors: David Z
authors: DZ
authors: D Argenio
authors: Institute for Therapeutic Innovation, Department of Medicine, University of Florida, Orlando.
authors: Ashley N
authors: AN
authors: Brown
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D002646:Chikungunya virus / Q000187:drug effects*; D002522:Chlorocebus aethiops; D004359:Drug Therapy, Combination / Q000379:methods; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D008962:Models, Theoretical; D011994:Recombinant Proteins / Q000494:pharmacology; D012254:Ribavirin / Q000494:pharmacology*; D014709:Vero Cells
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D012254:Ribavirin
keywords: antiviral combination therapy; chikungunya virus; interferon alfa; ribavirin