Amid initial hiccups related to coordination and logistics, the 15-day serological survey continued in some parts of the national capital for the second consecutive day on Sunday with 1,947 samples collected.
As part of the survey, blood samples of 20,000 people will be tested to ascertain the presence of anti-bodies, the Union health ministry has said.
The exercise will be jointly carried out by the National Centre for Disease Control (NCDC) and the Delhi government till July 10.
The survey commenced on Saturday and nearly 600 samples were collected on the first day.
According to a government official, 1,947 samples were collected on Sunday.
While in some districts like East and Northeast the survey will start from Monday, in some others, it started on Sunday.
Officials said there were some initial hiccups related to coordination and logistics.
There are no major issues but it requires persuasion to convince people to come forward and give their samples for COVID-19 testing, they added.
The districts have been given a fixed quota of sample collection, in accordance with various factors including population, the officials said.
In Delhi West, the survey commenced on Sunday in two areas -- Paschim Vihar and Paschim Puri -- and will start in full swing in 17 other areas from Monday, an official said, adding that the district has been given a target of collecting 3,000 samples.
In Delhi North, 140 samples were collected from Jahangirpuri, Swaroop Nagar and Model town on Sunday.
"We have to collect 1,058 samples. Four teams have been deployed and if needed, more will be formed," a North district official said.
A serology (antibody) test is largely used for surveillance among a community. It can be used on those who have already tested positive for COVID-19 or those asymptomatic, and can reveal insights into immunity against the coronavirus.