New Delhi, Fresh serological survey for Covid-19 has begun in the national capital on Saturday. It was confirmed by Delhi Health Minister Satyendar Jain.

"It's a technical process and will be conducted across the capital. We want to find out the change since the last survey," Jain said.

The last survey, conducted in June, had shown 22.86 per cent of the 21,387 people surveyed had developed anti-bodies against Covid-19. It also meant what percentage of the population was infected and had recovered.

Under the new survey, 150 teams will collect around 15,000 blood samples between August 1 and August 5 as per the Health Department guidelines. It's aimed at enumerating people who must have developed IgG (Immunoglobulin G) anti-bodies, indicating their exposure to coronavirus.

It will also help ascertain whether the capital is moving towards the herd immunity.

A Health Department official said the results were expected by August 15.

The survey will be carried out in all the 11 Delhi districts. Each team, comprising ASHA (accredited social health activist) workers, an auxiliary nurse midwife, a phlebotomist or a lab technician and a community volunteer, will collect 25-40 blood samples a day.

Eighteen state health department labs have been authorised to process the samples.

To ensure participation of people from all age groups, 25 per cent samples will be collected from those below 18 years, 50 per cent from 18-49 years and the rest from the people 50 years and above.

As per the Health Department, the highest number of samples (2,200) will be collected in the northwest district, followed by the west (2,145) and the central (1,548). The least 885 samples will be collected from the New Delhi district.

The people whose samples were taken in the first survey will not be approached and it will include only those who have no symptoms.

The earlier serological survey was conducted between June 27 and July 10 by the National Centre for Disease Control (NCDC). Most people surveyed didn't know they were infected.

After this, the Delhi government decided to conduct serological survey every month to gauge the level and the number of people with antibodies against the infection.

on Friday, Delhi reported 1,195 new cases and 27 deaths, taking the coronavirus tally to 1,35,598 and the toll to 3,963. While the recovery rate has risen to 89.18 per cent, the mortality rate declined to 2.92 per cent.