SUTRA: A Novel Approach to Modelling Pandemics with Applications to COVID-19.

In this paper, we present a new mathematical model for pandemics called SUTRA. The acronym stands for Susceptible, Undetected, Tested (positive), and Removed Approach. A novel feature of our model is that it allows estimation of parameters from reported infection data, unlike most other models that estimate parameter values from other considerations. This gives the model the ability to predict the future trajectory well, as long as parameters do not change. In addition, it is possible to quantify how the model parameter values were affected by various interventions to control the pandemic, and/or the arrival of new mutants. We have applied our model to analyze and predict the progression of the COVID-19 pandemic in several countries. We present our predictions for two countries: India and US. In both cases, the model-computed trajectory closely matches actual one. Moreover, our predictions were used by entities such as the Reserve Bank of India to formulate policy.