Rajesh Ranjan, Aryan Sharma, and Mahendra Verma; IIT Kanpur

India is exhibiting signs of a second wave of COVID-19 as already seen in the United States and several other European countries including France and the United Kingdom. Although the vaccination drive is expanded gradually to include all age groups, the emergence of several new mutants of the pathogen, which are highly transmissible, poses a health emergency situation. We have plotted the variation in basic Reproduction number, R, with time to understand the emerging dynamics of COVID-19 spread in key states and India as a whole.

1. Since late Feb 2021, the value of R is consistently above 1 clearly indicating a second wave. For nearly 5 months between Oct 2020 and Feb 2021, R stayed below 1 where pandemic was showing signs of decline. A relatively late arrival of the second wave in India, compared to those in several other countries in the world, could be due to the recent spread of more contagious mutants, although they are less virulent.

2. R-value on 27 March 2021 is approximately 1.26, which is very close to the value in early May 2020. Therefore, following the trend from the first wave, it may be estimated that the number of active cases is going to rise for the next 3-4 months unless the social distancing norms are strictly enforced, and vaccination efforts are expedited.

3. Second wave has an exponential growth with exponents bigger than the first one. Further, since the daily new cases (about 60,000) are already at the level of August 2020, it is expected that with the current growth trend the second peak will be higher than the first one.

4. Although Maharashtra contributes to nearly 70% of the daily new cases in the second wave, the rapid growth of cases in several other states such as Punjab, Haryana, Gujarat, Madhya Pradesh, Uttar Pradesh show reproduction number close to the national trend. These states may be a month behind Maharashtra and therefore it is necessary to curb this rise through strict social distancing practices with higher compliance as in the first phase.