A year after the initial wild-type Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) strains began their devastation of the world, they were supplanted by new variants of concern (VOC). In Ontario, Canada, the wild type was overtaken first by the Alpha/B1.1.17 variant, and then by the Delta/B.1.617 variant. The principal objective of the present study is to develop and apply a much expanded Susceptible-Infection-Recovered-type model to better understand the spread of multiple VOC, and assess the effectiveness of vaccination and non-pharmaceutical interventions (NPI). The model represents competition among VOC, and reveals their mutual inhibitory effects. By separately tracking asymptomatic and symptomatic infections, model simulations identify a significant role of vaccine breakthrough in the spread of Delta. Furthermore, the severity of a Delta outbreak depends not only on the NPI and vaccination rate but also on the vaccine types. Alarmingly, despite Ontario’s existing NPI and relatively successful vaccine rollout, a future, more dangerous VOC could potentially infect a significant fraction of the province’s population and overwhelm the health care system. To stop that VOC, the province may need the simultaneous and rapid deployment of a third booster vaccine and stringent NPI.
【저자키워드】 Diseases, Computational biology and bioinformatics, 【초록키워드】 severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, Vaccine, coronavirus, vaccination, Health care, VoC, severity, variant, variants of concern, Delta, Intervention, coronavirus 2, Spread, Health, Asymptomatic, outbreak, Effectiveness, respiratory, Canada, Health care system, Strains, Care, wild type, Booster vaccine, Inhibitory effects, NPI, strain, acute respiratory syndrome, fraction, wild-type, competition, symptomatic infections, vaccination rate, infect, initial, identify, develop, reveal, the vaccine, 【제목키워드】 SARS-CoV-2 variant, understanding,