90% In Delhi Have Covid Antibodies, Shows Sero Survey: Sources

More than 90 per cent of people in Delhi are carrying anti-bodies for coronavirus, sources said after the sixth sero-survey report of the national capital was prepped. Every district has registered no less than 85 per cent sero-positivity. More women than men have developed anti-bodies, sources said. The figure includes antibodies formed through vaccination, which has progressed at a rapid pace.

Till Sunday, more than two crore people in Delhi -- 86 per cent of the population -- received the first dose of vaccine. Nearly 48 per cent have received both doses.

Scientists are yet to be certain what percentage of antibody carrying population is required for herd immunity for Covid. The figure varies for various diseases.

The Delta variant had pushed the threshold for herd immunity to "well over 80 per cent and potentially approaching 90 per cent", according to an Infectious Diseases Society of America briefing in early August.

This was the first sero-survey conducted after the devastating second wave of Covid in April, which brought the city's healthcare system to its knees.

Delhi's first ever sero-survey conducted in June-end last year found Covid antibodies in 22.6 per cent of the samples. The number increased to 29.1 per cent in August and then dropped to 25.1 per cent in September. In October, it went up to 25.5 per cent.

In the fifth sero-survey conducted in January this year, anti-bodies were found in 56.13 per cent of the population.

The sixth sero-survey had started from September 24. For a week, around 28,000 samples were collected from 280 wards of Delhi. The survey was planned after the city was considered to have shaken off the Delta variant of the virus, which drove the second wave of infections in April.