Mathematical modeling of Covid-19: A brief survey of early models

The SARS-Cov-2 caused Covid-19 has been the major health concern of the entire world for more than 2 years now. Various pharmaceutical and non-pharmaceutical strategies are still being tried out and employed to bring an end to the spread of this deadly disease. Mathematical modeling techniques also have been widely used to study the dynamics and progression of the pandemic and to propose control measures. Thousands of modeling works, employing various techniques, were developed even in the early months after the emergence of the disease. The objective of this paper is to provide a brief survey of some of the early papers in this area, detailing the country wise distribution, the mathematical methods used and the proposed recommendations for disease control. In particular, methods based on integer and fractional order differential equations, statistical and stochastic techniques are delineated