COVID seems to come back every few months, but infections are generally mild – Professor

_{Professor Cowling, HKU}

“COVID seems to be coming back every few months with new Omicron subvariants,” Professor Ben Cowling, head of epidemiology at HKU, tells Sai Kung BUZZ. ” . . . The severity of infections hasn’t come down that much — not as much as we had been expecting. For this calendar year, COVID will have caused more hospitalisations and deaths than the flu, partly because the infection rate is higher and partly because the COVID infections still seem to be a bit more serious on average.” Nevertheless, the professor said, “At the minute COVID levels in the community are quite low.”

The Omicron subvariant, according to Wikipedia, was first detected in Botswana three years ago. It has now spread to become the pre-dominant variant in circulation around the world. Three doses of vaccine provide protection against severe disease and hospitalisation, Wikipedia says.

Back to Professor Cowling. He gave BUZZ a paper¹ based on a study of COVID in Hong Kong from March 2022 to October 2023. This concluded that “Community infections were generally mild, with asymptomatic infection comprising up to 25 per cent of infections. No hospitalisations or deaths occurred due to SARS-CoV-2 infection during the study period”. Although infections were mild, they weren’t increasingly so. About a third of participants with symptomatic infections reported that the symptoms severely affected daily life, even if they were not admitted to hospital, resulting in morbidity, absence from work or school . . .” etcetera.

Professor Ben Cowling MBE is the chair Professor of Epidemiology and Head of Biostatistics at the School of Public Health, University of Hong Kong. His research is mostly into infectious disease epidemiology, including field studies of respiratory virus transmission, the effectiveness of influenza vaccines and infection immunity. During the pandemic, Professor Cowling and his team shifted their focus to COVID. Outside HKU, the professor is editor-in-chief of Influenza and Other Respiratory Viruses and a member of the Centre for Communicable Disease Dynamics at the School of Public Health, Harvard University.

1. Clinical profile analysis of SARS-CoV-2 community infections during periods with omicron BA.2, BA.4/5, and XBB dominance in Hong Kong: a prospective cohort study. Yawei Wang, Hau Chi So, Nicole Ngai Yung Tsang, Siu Kan Kwok, Benjamin J Cowling, Gabriel M Leung MD, Dennis Kai Ming Ip, The Lancet Infectious Diseases, October 2024