A Nonlinear Mathematical Model for the Dynamics of the Omicron Wave

Over the COVID-19 pandemic millions of deaths and hospitalizations have been reported. Di erent SARS-CoV-2 variants of concern have been recognized during this pandemic and some of these variants of concern have caused uncertainty and changes in the dynamics. Recently, the Omicron variant has caused a large amount of infected cases in the US and worldwide. However, the average number of deaths during this Omicron wave has only slightly increased in comparison with previous SARS-CoV-2 waves. We study by a highly nonlinear mathematical model the COVID-19 pandemic situation during the Omicron wave. The novel model includes individuals who are vaccinated and asymptomatic which in uence the dynamics of the SARS-CoV-2. Moreover, the model considers the waning of the immunity and e cacy of the vaccine against the Omicron strain. This study uses the facts that the Omicron strain has a higher transmissibility than the previous circulating SARSCoV-2 strain but less deadly. Preliminary studies have found that Omicron has a lower case fatality rate compared to previous circulating SARS-CoV-2 strains. The simulation results show that even if the Omicron strain is less deadly it might cause more deaths, hospitalizations and infections. We provide a variety of scenarios that help to obtain insight about the Omicron wave and its consequences. We perform in silico simulations that explains from a mathematical viewpoint the large Omicron wave under various conditions related to the vaccines and transmissibility.