The next round of the monthly sero-prevalance survey in the national capital, which got delayed, will now begin from October 15, sources said on Wednesday.
The last survey was held from September 1-7 to better assess the Covid-19 situation here and formulate combat strategies.
The exercise was slated to begin from October 1, but got delayed as the results of the survey done last month was presented to the Delhi High Court on September 30.
"This month''s survey will now begin from October 15," an official source said.
The national capital recorded 39 Covid-19 fatalities on Tuesday, as the toll mounted to 5,581 while 2,676 fresh cases took the tally to over 2.95 lakh, authorities said.
The September survey had found that sero-prevalence of antibodies to Covid-19 had reduced to 25 per cent, from nearly 29 per cent recorded in the August exercise, among people in the national capital, the Delhi High Court was informed.
The September survey also found that nearly one-third of the participants with a past history of Covid-19 infection, "did not have detectable IgG antibodies".
"However, there is evidence that antibodies to Covid-19 may deplete over time," it added.
The sample size in the last month''s exercise was about 17,000.