Delhi Health Minister Satyendar Jain said on Tuesday that 56.13 per cent of those covered under the latest serological survey in the city in January have developed antibodies against coronavirus.
The minister also said Delhi was "moving towards herd immunity, but only experts will be able to give a clear picture".
The fifth sero survey -- the largest in the country so far -- was conducted from January 15 to January 23, he said.
At 62.18 per cent, Southwest Delhi district reported maximum seroprevalence. North Delhi at 49.09 per cent recorded the lowest, Jain said.
"A new, better technology was used during the survey. Samples were collected from every ward. In all, 28,000 samples were taken," a senior official said.
The minister said the number of cases, fatalities and hospital admissions have declined significantly, but insisted that people should continue to use masks for a few more months and maintain "Covid-19-appropriate behavior".
Jain said that three major changes were incorporated during the latest survey.
"We increased the sample size. Samples were collected on the basis of socio-economic conditions. A new, more sensitive kit was used and the testing was conducted at Institute of Liver and Biliary Sciences," he said.
The minister also informed that frontline workers will start getting Covid-19 vaccine jabs this week.
Nearly six lakh frontline workers, including government school teachers, MCD employees, police personnel, ASHA and ANM workers, are expected to be administered the vaccine.