The fifth round of seroprevalence survey conducted in Delhi showed that 56 per cent of the people who were surveyed have developed antibodies against Covid-19, said Delhi Health Minister Satyendar Jain.

He added that we should still be following COVID protocol, and that “we should not get into discussions over herd immunity.”

“This was the largest survey in any state involving around 28,000 samples conducted from January 15 to 23. Delhi has largely won over COVID-19, though we should continue to practice Covid-appropriate behaviour.”
Satyendar Jain, Delhi Health Minister

The survey results showed that Delhi’s north district had the lowest seroprevalence - or the number of people with antibodies which was 49 per cent. Meanwhile, the southeast district had the highest at 62.18 per cent.

“The last survey found 25-26 per cent seroprevalence. This means Delhi is inching towards herd immunity. Cases are also declining at less than 200 per day and low positivity rates. But I would appeal not let your guard down. Keep your masks on.”
Satyendar Jain, Delhi Health Minister

What Does this Mean for Herd Immunity?

Herd immunity was a much-used phrase throughout the pandemic, and like many new scientific words that came into our lexicon, we often used it wrong.

“We use the phrase herd immunity when talking about vaccines. Medically, for the same concept in a pollution we need to talk in terms of seropositivity.”
Dr Sumit Ray, senior consultant of Critical Care Medicine at Holy Family Hospital in Delhi

He explained that high seropositivity after a high number of cases made sense. “Let’s take the example of Dharavi. The seropositivity is so high after it being full of cases, which makes sense. Dr Jayaprakash Muylil has said that there are regions within cities where seropositivity has reached 60-70 per cent, even when overall seropositivity within cities would be around 30 per cent.”

If you have high seropositivity in the cities, this reduces transmission significantly. Dr Ray says that now we need to gather more specific data.

“We need to analyse larger seropositivity data from smaller regions within cities and this data needs to be made public. There is a possibility that certain areas have reached good levels and will have fewer cases - but this does not mean there will not be another surge. You have to be careful.”
Dr Sumit Ray, senior consultant of Critical Care Medicine at Holy Family Hospital in Delhi

Published: 02 Feb 2021,04:43 PM IST

ADVERTISEMENT
SCROLL FOR NEXT