應學院邀請，蘭州大學王賓國教授将在線作學術報告。
報告題目：A mathematical model reveals the influence of NPIs and vaccination on SARS-CoV-2 Omicron Variant
報告摘要：In this talk, an SVEIR SARS-CoV-2 Omicron variant model is proposed to provide some insights to coordinate non-pharmaceutical interventions(NPIs) and vaccination. Mathematically, we define the basic reproduction number $R_0$ and the effective reproduction number $R_e$ to measure the infection potential of Omicron variant and formulate an optimal disease control strategy.Our inversion results imply that the sick period of Omicron variant in United States is longer than that of Delta variant in India. The decrease of the infectious periodof the infection with infectiousness implies that the risk of hospitalization is reduced; but the increasing periodof the infection with non-infectiousness signifies that Omicron variant lengthens the period of nucleic acid test being negative. Optimistically, Omicron's death rate is only a quarter of Delta's. Moreover, we forecast that the cumulative cases will exceed 100 million in United States on 28 February, 2022 and the daily confirmed cases will reach a peak on 2 February, 2022. The results of parameters sensitivity analysis imply that NPIs are helpful to reduce the number of confirmed cases. Especially, NPIs are indispensable even if all the people were vaccinated when the efficiency of vaccine is relatively low. By simulating the relationships of the effective reproduction number $R_e$, the vaccination rate and the efficacy of vaccine, we find that it is impossible to achieve the herd immunity without NPIs while the efficiency of vaccine is lower than 88.7%. Therefore, the herd immunity area is defined by the evolution of relationships between the vaccination rate and the efficacy of vaccine. Finally, we present that the disease-induced mortality rate demonstrates the periodic oscillation and an almost periodic function is deduced to match the curve.
報告時間：2022年11月17日15:00
邀 請 人：強立忠博士
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報告人簡介
王賓國，理學博士，蘭州大學77779193永利教授，碩士導師。美國“數學評論”評論員。主要從事非自治情形下傳染病模型動力學行為研究。相關結果發表在J. Dyn. Diff. Equ.，J. Diff. Equ.，J. Math.Biol., European Journal of Applied Mathematics，Zeitschrift fuer Angewandte Mathematik und Physik，Discrete and Continuous Dynamical Systems A，Discrete and Continuous Dynamical Systems B,Nonlinear Dynamics上。主持天元基金、國家自然科學基金青年基金、甘肅省青年基金、國家自然科學基金卓越青年基金子課題各一項。參與國家自然科學基金重點項目一項。
