1 Department of Medical Microbiology and Immunology and Li Ka Shing Institute of Virology, University of Alberta, Katz Group Centre for Pharmacy and Health Research, University of Alberta, Edmonton, Canada.
2 Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada.
3 Department of Medical Microbiology and Immunology and Li Ka Shing Institute of Virology, University of Alberta, Katz Group Centre for Pharmacy and Health Research, University of Alberta, Edmonton, Canada. ringham@ualberta.ca.