Emergence and spread of SARS-CoV-2 variants of concern in Canada: a retrospective analysis from clinical and wastewater data oleh David Champredon, Devan Becker, Shelley W. Peterson, Edgard Mejia, Nikho Hizon, Andrea Schertzer, Mohamed Djebli, Femi F. Oloye, Yuwei Xie, Mohsen Asadi, Jenna Cantin, Xia Pu, Charles A. Osunla, Markus Brinkmann, Kerry N. McPhedran, Mark R. Servos, John P. Giesy, Chand Mangat