Monthly sero-surveys, next to be conducted from August 1-5, says Delhi health minister

The previous sero-survey was conducted in Delhi during June 27-July 10, usung more than 21,000 samples. The results of the survey, shared by the National Centre for Disease Control (NCDC), suggested around 23% of the city’s population or about one in four persons may have been exposed to the Sars-CoV-2 virus.

A sero-survey will be conducted again in the capital between August 1 and 5 and the government plans to make it a monthly exercise, Delhi home minister Satyendar Jain said on Wednesday.

Asked about herd immunity, Satyendar Jain said even experts differ on this concept (ANI)

Samples for the upcoming sero-survey will be collected from across Delhi and a strategy is being drafted for this. The sample size will be “not less than the previous sero-survey”, Jain told a press briefing, the first one addressed by him after he recovered from Covid-19 and returned to work.

The previous sero-survey was conducted in Delhi during June 27-July 10, usung more than 21,000 samples. The results of the survey, shared by the National Centre for Disease Control (NCDC), suggested around 23% of the city’s population or about one in four persons may have been exposed to the Sars-CoV-2 virus.

“Sero-survey identifies people who have recovered from the disease. The 23% result of the previous survey is most likely to be people who got infected around mid-June, because antibodies take around 15 days to develop. It is almost a month now. To monitor trends, the government plans to make it a monthly exercise. We shall be doing the next sero-survey between August 1 and 5,” said Jain.

Asked if this could be called community spread, Jain said: “The disease has definitely spread in the community and the results reflect that. Whether one can call it, community spread is a very technical thing as per the guidelines and protocols that are followed.”

Citing the results of the previous sero-survey, which was done in line with recommendations from Union home minister Amit Shah on June 21, Jain said: “Around 77% of people are still vulnerable and we cannot be complacent. We should be serious about maintaining social distance, wearing masks and washing our hands regularly.”

He added, “For the upcoming survey, we are chalking out a strategy. It will be spread across the city, cover both containment zones and normal areas, include individuals of different age groups and the sample size will be not less than the previous survey.”

Asked about herd immunity, Jain said even experts differ on this concept. “Usually, it is perceived as a stage when around 40% to 70% people have recovered from the disease. We cannot comment on herd immunity at this stage. We will get a better picture of that after the number of fresh cases stop emerging,” he said.