. 2021 Aug 14;151:69–75. doi: 10.1016/j.patrec.2021.07.027

Table 2.

Five significant changepoints of Confirmed series of INDIA

Change Point Date	Lockdown Period	Possible reason
29-03-2020 1^st Changepoints shown in Fig. 2	Lockdown 1.0 continued from 23^rd March to 14^th April 2020	This point falls in the Lockdown 1.0. From covid19india.org, it is found that there is a sudden drop in the number of corona cases on 29^th March viz. only 3.6% patients were identified between 28^th(987 cases) to 29^th(1024) March. This can be attributed to the increase in COVID testing. Towards the end of the first lockdown, the rate of growth of COVID infections in India had significantly slowed down from a rate of doubling every three days before the lockdown to one of doubling every eight days on 18^th April 2020.
07-06-2020 2^nd Changepoints shown in Fig. 2	Unlock 1.0 (1^st -30 th June 2020)	This changepoints falls in the Unlock 1.0 period. The changepoints shows there is a sharp rise of the confirmed cases and this can be attributed to the Unlock 1.0. As the Ministry of Home Affairs lifted the lockdown restrictions and imposed lockdown in the containment zones, while allowed activities in other zones in a phased manner. Unlock 1.0 reopened shopping malls, religious places, hotels, and restaurants from 8^th June 2020. Large gatherings were still banned but there were no restrictions on interstate travel. Night curfews were in effect from 9 p.m. to 5 a.m. in all areas and state governments were allowed to impose suitable restrictions on all activities.
17-08-2020 3^rd Changepoints shown in Fig. 2	Unlock 3.0 (1^st – 31^st August 2020)	This point shows a steady decline of the confirmed cases. This is because; Unlock 3.0 started maintaining strict parameter control such as intensive contact tracing, house-to-house surveillance and other clinical interventions. The guidelines for the usage of ArogyaSetu, social distancing and masks were strengthened. Maharashtra and Tamil Nadu imposed a lockdown for the whole month, while West Bengal imposed lockdowns twice in a week. Medical infrastructures were strengthened that impacted in the increase in recovery rate.
29-10-2020 4^th Changepoints shown in Fig. 2	Unlock 5.0 (1^st – 31^st October 2020)	This Changepoints shows a sharp decrease in the number of confirmed cases. The information available in covid19india.org validates the changes illustrated by 4^th Changepoints of Fig. 2. It is observed that rate of recovery was very close to rate of confirmed cases. It was made possible as Government strictly maintained the covid control parameters and made compulsory face coverings/masks in public places, workplaces and during transport.
01-01-2021 5^th Changepoints shown in Fig. 2	5^th Changepoints shows flattening of the disease trend	The 5^th Changepoints shows flattening of the disease curve for a short while and then a gradual increase in the number of cases observed after February 2020. This situation can be attributed to the withdrawal of lockdowns and opening of Universities, colleges and public places.