aDivision of Infectious Diseases, Department of Medicine, School of Medicine

bInstitute for Global Health and Infectious Diseases

cDepartment of Health Behavior, Gillings School of Global Public Health, University of North Carolina at Chapel Hill

dDepartment of Pharmacology, School of Medicine

eLineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA

Correspondence to Joseph A. Duncan, 111 Mason Farm Road, Medical Biomolecular Research Building, Rm 8341, Chapel Hill, NC 27599, USA. E-mail: [email protected]