A cluster randomised trial of cloth masks compared with medical masks in healthcare workersA cluster randomised trial of cloth masks compared with medical masks in healthcare workers C Raina MacIntyre1, Holly Seale1, Tham Chi Dung2, Nguyen Tran Hien2, Phan Thi Nga2, Abrar Ahmad Chughtai1, Bayzidur Rahman1, Dominic E Dwyer3, Quanyi Wang41Faculty of Medicine, School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia2National Institute of Hygiene and
