A group of scientists including SAGE member Prof Susan Michie have analysed responses taken on behalf of the Department of Health and Social Care in a series of 21 surveys, each of abour 2,000 people, from 5 March to 2 August. We can expect that of the order of 100 people in each survey would have had Covid-19. The report has not yet been peer-reviewed for publication. The results make depressing reading as to the overall effectiveness of our national system for suppressing Covid-19 infection.