Mumbai's municipal corporation - the BMC - has revealed the findings of Mumbai Sero Survey. The sero-survey on about 7000 people found that 57% of those tested from slums and 16% from non-slum areas developed antibodies against COVID19. Govindraj Ethiraj talks to Dr. Daksha Shah, Dr. Ullas Kolthur Seetharam and Jayanthi Shastri about the execution and findings of the serological survey, the transmission of the disease and how the data from the survey will help health authorities tackle the COVID-19 crisis. Dr. Daksha Shah, Deputy Executive Health Officer, BMC. Dr. Ullas Kolthur Seetharam, Professor, Department of Biological Sciences, Tata Institute of Fundamental Research. Jayanthi Shastri, Head of Molecular Diagnostic Lab, Kasturba Hospital.