According to a serological survey conducted in Delhi, it was found out that 79 out of the 257 patients who recovered from coronavirus did not develop antibodies against the virus.
The survey was conducted by a team of scientists and experts at Maulana Azad Medical College (MAMC). Blood samples of 257 people who had tested COVID-19 positive earlier and then recovered, were also taken during the survey to test if they had antibodies.
The survey was conducted in August, for which over 15,000 representative samples were taken from 11 districts and tested for antibodies (IgG) against the virus, reported NDTV.
The survey was conducted for a comprehensive assessment of the COVID-19 situation in the capital and to formulate strategies accordingly. Geographical areas, age groups, gender and economic class were some of the factors taken into consideration for the assessment.
About 29.1 per cent of people had developed antibodies in the national capital. Of the number of people with antibodies, 28.3 per cent were male, 32.2 per cent were females.
Of the total samples, 25 per cent belonged to the age group of fewer than 18 years, another 50 per cent from 18-49 years of age, while the remaining 25 per cent were those in the age group of 50 years or above, the Delhi health minister informed the media.
In response to the survey, experts say that people whose samples were collected might have tested positive for the virus at the early stage of the virus, therefore, their antibodies now might have disappeared.
But in most cases, the memory cells would remember the virus and trigger an immune response if a person who has recovered from COVID-19 is again attacked by the virus, they further said.
The report also said the participants who were living in or had ever lived in a containment zone in Delhi, had a 'significantly higher seroprevalence' than those who had never lived in it.