SCMP digital editor Jarrod Watt speaks with Professor Ben Cowling, Chair Professor of Epidemiology at the School of Public Health at the University of Hong Kong. Cowling has been on previous episodes of Inside China, but in this special feature he discusses the Omicron variant, the need for travel bans, the science behind 21 day quarantine, and delves into his experience of Hong Kong quarantine. Hear about air purifiers, "selfish masks" and his predictions for Hong Kong and mainland China in…