A sero-prevalance survey conducted in the first week of August in Delhi has found that 79 of the 257 people who recovered from Covid-19 did not have antibodies against the virus. About 15,000 representative samples were taken in the August 1-7 survey from 11 districts and tested for antibodies (IgG) against the virus. The exercise was undertaken for a comprehensive assessment of the Covid-19 situation in Delhi and to formulate strategies based on its findings.