The Clinical Severity of COVID-19 Variants of Concern: Retrospective Population-Based Analysis

Sean P Harrigan   ^{1, 2} , MSc ;   Héctor A Velásquez García   ² , MPH, MS, MD, PhD ;   Younathan Abdia   ² , PhD ;   James Wilton   ¹ , MPH ;   Natalie Prystajecky   ^{1, 3} , PhD ;   John Tyson   ^{1, 3} , PhD ;   Chris Fjell   ^{1, 3} , PhD ;   Linda Hoang   ^{1, 3} , MD ;   Jeffrey C Kwong   ^{4, 5, 6, 7} , MD ;   Sharmistha Mishra   ^{4, 7, 8, 9, 10, 11} , MSc, MD, PhD ;   Linwei Wang   ⁸ , MSc ;   Beate Sander   ^{4, 5, 9, 12} , RN, MBA, MEcDev, PhD ;   Naveed Z Janjua   ^{1, 13, 14} , MBBS, DrPH ;   Hind Sbihi   ^{1, 13} , BEng, MSc, PhD

¹ BC Centre for Disease Control, Vancouver, BC, Canada

² University of British Columbia Centre for Disease Control, Vancouver, BC, Canada

³ Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada

⁴ Institute for Clinical Evaluative Sciences, Toronto, ON, Canada

⁵ Public Health Ontario, Toronto, ON, Canada

⁶ Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada

⁷ Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada

⁸ MAP Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, ON, Canada

⁹ Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada

¹⁰ Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada

¹¹ Department of Medicine, University of Toronto, Toronto, ON, Canada

¹² Toronto Health Economics and Technology Assessment Collaborative, University Health Network, Toronto, ON, Canada

¹³ School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada

¹⁴ Centre for Advancing Health Outcomes, St Paul's Hospital, Vancouver, BC, Canada