First Wave vs Second Wave

By Arun Mitra in COVID Epidemiology R

May 12, 2021

The abrupt onset of the second wave of COVID-19 in India has taken the country by storm. With over 4,00,000 cases being reported daily, India has over 37,00,000 active cases as of 12, May 2021. This post aims to estimate the epidemiological parameters of COVID-19 epidemic in India during the first and second waves.

As discussed in the previous post, India’s epidemic curve suggests an ongoing second wave of COVID-19 infections in the country. However, the magnitude and force of infection of the second wave is considerably different from the first wave. Though a multitude of factors such as the lack of a nation-wide lockdown, mutations in the virus, laxity in preventive measures and shifting priorities of the government may be attributed to the second wave.

The epidemic curve of COVID-19 in India can be divided into two time periods based on the valley between two peaks.

Transmission Parameters

It is clear from the above epidemic curve that there were two distinct waves of COVID-19 epidemic in India. The first wave which is estimated to have peaked on 2020-09-19 with a 95% CI of being between 2020-09-18 and 2020-09-21. This has been estimated by running 100 simulations based on the epidemic curve of COVID-19 in India. The growth rate of the first wave until the peak has been 3.53% (95% CI 3.39 - 3.67) while after the peak had a rate of decline of -1.48% (95% CI -1.51 - -1.46).

Posted on:
May 12, 2021
26 minute read, 5347 words
COVID Epidemiology R
See Also:
Estimating Effective Reproduction Number for the COVID-19 Epidemic in India
COVID-19 Epidemic in India