The impact of social and physical distancing measures on COVID-19 activity in England: findings from a multi-tiered surveillance system by Bernal, JL, Sinnathamby, MA, Elgohari, S, Zhao, H, Obi, C, Coughlan, L, Lampos, V, Simmons, R, Tessier, E, Campbell, H, McDonald, S, Ellis, J, Hughes, H, Smith, G, Joy, M, Tripathy, M, Byford, R, Ferreira, F, de Lusignan, S, Zambon, M, Dabrera, G, Brown, K, Saliba, V, Andrews, N, Amirthalingam, G, Mandal, S, Edelstein, M, Elliot, AJ, Ramsay, M