New Delhi: While on the one hand vaccination has started against coronavirus in full steam in India, the results of the fifth serological survey in Delhi have brought both relief and surprise. According to the latest serosurvey, 1 in 2 people in Delhi were likely infected by Covid-19 and then got cured.
New Delhi: While on the one hand vaccination has started against coronavirus in full steam in India, the results of the fifth serological survey in Delhi have brought both relief and surprise. According to the latest serosurvey, 1 in 2 people in Delhi were likely infected by Covid-19 and then got cured.
Multiple rounds of serosurveys have been conducted by the Delhi government to assess the spread of coronavirus infection in the national capital. The fifth and the largest serosurvey of Delhi was conducted in January 2021. In a serosurvey, samples of blood are collected from the person`s body and then medical team tests whether antibodies have been formed against coronavirus in the blood or not. According to Delhi government sources, the preliminary trend of Delhi`s fifth serosurvey has revealed that 60 per cent of people in one particular district in Delhi have been found to have Covid-19 antibodies. This means that they were unknowingly infected with coronavirus and got cured later. Whereas in other districts, more than 50 per cent of people were found to have antibodies and had therefore come in contact with coronavirus.
Delhi has a population of more than 2 crores and the fifth serosurvey indicates that around 1 crore population has been cured after being infected with coronavirus.
The high prevalence of coronavirus antibodies indicates that the capital may have reached the stage of herd immunity.
Dr Arun Gupta, President of Delhi Medical Council has explained herd immunity in 3 parts:
1. It is very important to first understand what is herd immunity. If a large population has an antibody against a disease, then it stops the spread of that disease and the rest of the population can be saved from infection.
2. Herd immunity can occur in two ways -- one by the natural spread of infection or by vaccination. As scientists and doctors, we always wish that herd immunity comes from vaccination.
3. If antibodies against infection are found in 60 per cent of the population, then, in this case, we can assume that the rest of the population which does not have antibodies can also be protected from the infection.
Dr Gupta further said that the result of serosurvey in Delhi is very good. "This is why the outbreak of coronavirus is decreasing in Delhi. Also, the way the vaccination drive is going on, Delhi will soon get over Covid-19," he said.
The fifth serosurvey of Delhi is the largest serosurvey to date. A total of 28,000 people were sampled in this survey. 100 samples were taken from every municipal ward of Delhi. The survey has been conducted from January 10 to January 23. The first serosurvey in Delhi was conducted in June-July in which antibodies were found in 23.4 per cent people. Antibodies were found in 29.1 per cent of people in August. This was followed by antibodies in 25.1 per cent in September and 25.5 per cent in October.
