medRxiv preprint doi: https://doi.org/10.1101/2020.12.10.20246827; this version posted December 11, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . Projecting the impact of a two-dose COVID-19 vaccination campaign in Ontario, Canada Thomas N. Vilches,1 Kevin Zhang,2,† Robert Van Exan,3 Joanne M. Langley,4 Seyed M. Moghadas5 1 Institute of Mathematics, Statistics and Scientific Computing, University of Campinas, Campinas SP, Brazil 2 Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8 Canada 3 Immunization Policy & Knowledge Translation, Trent Lakes, Ontario, K0M 1A0, Canada 4 Canadian Center for Vaccinology, Dalhousie University, IWK Health Centre and Nova Scotia Health Authority, Halifax, Nova Scotia, B3K 6R8 Canada 5 Agent-Based Modelling Laboratory, York University, Toronto, Ontario, M3J 1P3 Canada †Corresponding author:
[email protected] Abstract Background: Results of phase III vaccine clinical trials against COVID-19, although encouraging and well above initial expectations, have only reported on efficacy against disease and its severity. We evaluated the impact of vaccination on COVID-19 outbreak and disease outcomes in Ontario, Canada. Methods: We used an agent-based transmission model and parameterized it with COVID-19 characteristics, demographics of Ontario, and age-specific clinical outcomes derived from outbreak data. We implemented a two-dose vaccination program, prioritizing healthcare workers and high-risk individuals, with 40% vaccine coverage and vaccine efficacy of 95% against disease.