2022威廉希尔非线性分析、微分方程与动力系统系列报告

本期组织：薄伟健

主办单位：williamhill威廉希尔官网

基金资助：国家自然科学基金、陕西省杰出青年科学基金

联系人：吴事良手机:18392190403 E-mail:slwu@xidian.edu.cn

薄伟健手机:18394665867E-mail:wjbo@xidian.edu.cn

报告信息

A mathematical model reveals the influence of NPIs and vaccination on SARS-CoV-2 Omicron Variant

王宾国 兰州大学

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 and the effective reproduction number 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 period of the infection with infectiousness implies that the risk of hospitalization is reduced; but the increasing period of 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, 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.

报告人简介：王宾国，理学博士，兰州大学williamhill威廉希尔官网教授，硕士导师。美国“数学评论”评论员。主要从事非自治情形下传染病模型动力学行为研究。相关结果发表在J. Dyn. Diff. Equ.，J. Dyn. 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、国家自然科学基金青年基金、甘肃省青年基金、国家自然科学基金卓越青年基金子课题各一项。参与国家自然科学基金重点项目一项。