Comparing Public Perceptions and Preventive Behaviors During the Early Phase of the COVID-19 Pandemic in Hong Kong and the United Kingdom: Cross-sectional Survey Study - Bowman,L; Kwok,KO; Redd,R; Yi,Y; Ward,H; Wei,WI; Atchison,C; Wong,SY-S (JOURNAL OF MEDICAL INTERNET RESEARCH, 2021)