Plausible Explanation for the Third COVID-19 Wave in India and Its Implications

Abstract

Recently some of us reported Monte Carlo simulations of COVID-19 spread as a contact process, using random walkers on a two-dimensional plane. The calculations were shown to follow observed growth trajectories for secondary and tertiary waves of infection in countries such as the USA, India, South Africa and Serbia. However, they failed to predict the Omicron-driven third wave for India. Here we present a more complete set of simulations for India, that take into consideration two important aspects not incorporated in previous work. These include the stochastic movement of an erstwhile immobile (and protected) fraction of the population because of the easing of restrictions, and a possible reinfection of some recovered individuals, arising from their exposure to a new variant of the SARS-CoV-2 virus. These extended random walk Monte Carlo simulations show the third COVID-19 wave for India that was missing in the earlier calculations. They also suggest an additional fourth wave for India, which was indeed observed during approximately the same time period as the model prediction.

Note:
Funding Information: ST acknowledges funding support from the National Research Foundation (South Africa) under grant number 85100.

Conflict of Interests: The authors declare no competing interests.

Keywords: COVID-19, random walk, Monte Carlo simulations, epidemic waves

JEL Classification: C63, I1