NEW DELHI: A serological survey covering more than 20,000 people across 11 districts in Delhi, conducted between June 27 and July 10 showed that most of the Delhiites have developed anti-bodies and attained immunity without any need of medical attention. The study says that around one-fourth of Delhi has been already exposed to the dangerous coronavirus.

Dr SK Sareen, Director, Institue of Liver and Biliary Sciences speaking to a news channel said, "Just about six percent of Delhiites tested positive for COVID-19, but one-fourth of Delhi got immunity. This is referred to as herd immunity and these people have developed immunity even without getting vaccine. However though these self-acquired antibodies are yet to be titrated, their presence means that these individuals have been infected and managed to clear the virus."

National Centre for Disease Control (NCDC) director Dr. Sujeet Kumar Singh said that "Containment measures need to continue with the same rigour, Physical distancing, use of face mask, hand hygiene and cough etiquette must be followed strictly." He further added that nearly six months after the outbreak, just 22.86 per cent of the population is affected. This can be due to the efforts made to avoid the spread of infection by locking and other containment measures.

He also asserted that, "An earlier sero survey conducted by the Indian Council of Medical Research (ICMR) in containment zones showed prevalence of 34% in Ahmedabad and 9-11% in Delhi."

Sero-survey or sero-prevalence analysis includes testing of the blood serum of individuals to screen for antibody prevalence against the infection. In Delhi, the National Centre for Disease Control, in partnership with the Delhi government, conducted a survey of 21,387 samples between June 27 and July 10. The Union Health Ministry said, "The results of the sero-prevalence study show that on average, across Delhi, the prevalence of IgG antibodies is 23.48 per cent. The study also indicates that a large number of infected persons remain asymptomatic."

The number of active cases in Delhi also declined to just around 15,000. The highest number of active cases recorded in the city was just over 28,000 registered at the end of June. In Delhi there are 124K confirmed coronavirus cases till date and 105K people have been recovered. A total of 3,663 people have died due to COVID-19 infection.