Unfinished Epidemic of Infectious Diseases
Epidemiology and Control of COVID-19 in Hong Kong
Professor Benjamin J Cowling
Chair Professor of Epidemiology and
Head of Division of Epidemiology and Biostatistics, School of Public Health, The University of Hong Kong
Biography
Professor Benjamin J Cowling is currently Chair Professor of Epidemiology and Head of Division of Epidemiology and Biostatistics in the School of Public Health at The University of Hong Kong, and co-Director of the WHO Collaborating Centre for Infectious Disease Epidemiology and Control. He conducts research into the epidemiology of respiratory virus infections, with a focus on transmission dynamics and the effectiveness of control measures including vaccination. Since early 2020 he has conducted research on the epidemiology and control of COVID-19 including highly cited publications in NEJM, Science and Nature Medicine. He has authored more than 500 peer-reviewed journal publications to date. He is Editor-in-Chief of Influenza and Other Respiratory Viruses, and an Associate Editor of the journal Emerging Infectious Diseases. His work is supported by a number of major grants from funding bodies in Hong Kong and the United States. In June 2021 he was awarded an MBE by Her Majesty Queen Elizabeth II for services to public health and COVID-19 research.
Abstract
In early 2020, Hong Kong was one of the first-affected locations outside of mainland China. However, in the first two years of the pandemic timely public health measures as part of a “Dynamic Zero Covid” strategy were able to successfully control a number of surges in daily case numbers, restricting the incidence of confirmed cases below 1% of the population. Nevertheless, a major epidemic in Omicron BA.2 infections resulted in more than a million confirmed infections and more than 9,000 deaths. Epidemiological analyses have improved our understanding of disease dynamics and the impact of control measures. For example, one of the most interesting phenomena in transmission has been “super-spreading”, in which we have determined that a minority of infections are responsible for a majority of transmission events. In recent work, Professor Cowling has been examining how and why superspreading dynamics might vary over time, and epidemic phase bias. While mass vaccination provides a pathway back to a new normal in most parts of the world, the Hong Kong government is following the strategy in mainland China of continuing “Dynamic Zero Covid” even when population immunity has reached a high level. Community studies by Professor Cowling’s team provide evidence on levels of infections and immunity, and allow them to contrast the difference in effectiveness of the inactivated vaccine (Sinovac) and the mRNA vaccine (BioNTech/Fosun Pharma/Pfizer) being used in Hong Kong.