medRxiv preprint by Nuffield Non-Stipendiary Research Fellow Thomas Rawson, Pablo N. Perez-Guzman, Edward S. Knock, Christian Morgenstern, Nuffield Non-Stipendiary Research Fellow Daniel Valdenegro, Katy A.M. Gaythorpe, Lilith K. Whittles, Wes Hinsley, Raphael Sonabend, Richard G. FitzJohn, Anne Cori, Nuffield Senior Research Fellow Jennifer Beam Dowd, Jakub Bijak, Neil M. Ferguson and Nuffield Fellow Melinda C. Mills