A pragmatic cluster randomised controlled trial of air filtration to prevent symptomatic winter respiratory infections (including COVID-19) in care homes (AFRI-c) in England: Trial... door Rachel C M Brierley, Jodi Taylor, Nicholas Turner, Sophie Rees, Joanna Thorn, Chris Metcalfe, Emily J Henderson, Clare Clement, Tomas J Welsh, Karen Sargent, Gemma Morgan, Derren Ready, Dominic Mellon, Liping Wen, Ruth Kipping, Alastair D Hay