  The present ongoing global pandemic caused by SARS-CoV-2 virus is creating
havoc across the world. The absence of any vaccine as well as any definitive
drug to cure, has made the situation very grave. Therefore only few effective
tools are available to contain the rapid pace of spread of this disease, named
as COVID-19. On 24th March, 2020, the the Union Government of India made an
announcement of unprecedented complete lockdown of the entire country effective
from the next day. No exercise of similar scale and magnitude has been ever
undertaken anywhere on the globe in the history of entire mankind. This study
aims to scientifically analyze the implications of this decision using a
kinetic model covering more than 96% of Indian territory. This model was
further constrained by large sets of realistic parameters pertinent to India in
order to capture the ground realities prevailing in India, such as: (i) true
state wise population density distribution, (ii) accurate state wise infection
distribution for the zeroth day of simulation (20th March, 2020), (iii)
realistic movements of average clusters, (iv) rich diversity in movements
patterns across different states, (v) migration patterns across different
geographies, (vi) different migration patterns for pre- and post-COVID-19
outbreak, (vii) Indian demographic data based on the 2011 census, (viii) World
Health Organization (WHO) report on demography wise infection rate and (ix)
incubation period as per WHO report. This model does not attempt to make a
long-term prediction about the disease spread on a standalone basis; but to
compare between two different scenarios (complete lockdown vs. no lockdown). In
the framework of model assumptions, our model conclusively shows significant
success of the lockdown in containing the disease within a tiny fraction of the
population and in the absence of it, it would have led to a very grave
situation.
