1. Elizabeth C. Lowcock, Laura C. Rosella, and Natasha Crowcroft are with the Department of Surveillance and Epidemiology, Public Health Ontario, Toronto, Canada, and the Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario. Julie Foisy is with the Department of Surveillance and Epidemiology, Public Health Ontario. Allison McGeer is with the Department of Microbiology, Mount Sinai Hospital, Toronto, Ontario, and the Dalla Lana School of Public Health.