starting two decades before covid, sars and mers both caused by different forms of coronavirus, spread across parts of asia and the middle east. news: hong kong's airport is one of the busiest in the world. - a single infected airline passenger can carry a virus anywhere - in the world in a matter of hours. professor heymann played a key role in managing that first sars outbreak for the world health organization. what effect do you think having a serious outbreak of those two previous coronaviruses had on countries such as singapore, japan, south korea, taiwan and hong kong? i believe they had a profound effect on those countries. in fact, i visited some of those countries during the period after sars and before the current pandemic, and some of those countries had actually established isolation wards with hundreds of beds in their hospitals.