An SEIARD- based model with multi-strain and vaccine is proposed.
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Control reproduction number, stability, local and global sensitivity analysis are evaluated for the multi-strain.
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Alpha variant was slow to become the dominant strain because it had higher transmission.
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Delta variant become faster the dominant strain due to the fact it had higher transmission and immune evasion provided by the vaccine.
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The model was fitted with data from the USA.
Abstract
Multiple strains of the SARS-CoV-2 have arisen and jointly influence the trajectory of the coronavirus disease (COVID-19) pandemic. However, current models rarely account for this multi-strain dynamics and their different transmission rate and response to vaccines. We propose a new mathematical model that accounts for two virus variants and the deployment of a vaccination program. To demonstrate utility, we applied the model to determine the control reproduction number and the per day infection, death and recovery rates of each strain in the US pandemic. The model dynamics predicted the rise of the alpha variant and shed light on potential impact of the delta variant in 2021. We obtained the minimum percentage of fully vaccinated individuals to reduce the spread of the variants in combination with other intervention strategies to deaccelerate the rise of a multi-strain pandemic.
