Going Viral

As a secondary school student, Professor Yuen Kwok-yung, Henry Fok Professor in Infectious Diseases, was a keen member of the astronomy club. Little did he realise that his fascination with the universe would lay the seeds for his future career at the opposite scale – as a microbiologist – with globally significant consequences.

Professor Yuen is the top microbiologist in the nation, according to Research.com 2024 ranking, and among the top 10 in the world. He and his team have discovered more than 100 novel microbes – fungi, parasites, bacteria, and viruses including SARS-CoV-1 that led to the 2003 SARS outbreak. He was the corresponding author of a paper on person-to-person transmission of the COVID-19 virus, SARS-CoV-2, that was named one of the 34 landmark papers in The Lancet’s 200-year history.

His ability to wade into the unknown and painstakingly sift through life at the molecular level started way back in his skygazing days.

“There are billions of stars, and it takes a lot of effort to find the one you’re interested in. You start from a bright one and move towards the less bright ones until finally you find it, like a diamond in a sea of sand. Today, instead of using a telescope, I use the microscope or genetic techniques to find new viruses and other microbes. That, to me, is basically the same as finding a star in the night sky,” he said.

A fateful decision

The line between those two ends evolved in a slow, serendipitous fashion. Professor Yuen graduated from HKU’s Medical Faculty in 1981 with a distinction in medicine. The natural next step would have been to join Queen Mary Hospital among the other top graduates. But he was persuaded to pursue a higher calling and spent the next six years at United Christian Hospital (UCH).

“One of my classmates challenged me that everyone with a distinction wants to go to Queen Mary, so Queen Mary doesn’t need me. UCH at that time offered no housing allowance and no systematic specialist training, but it was in Kwun Tong where there were a lot of poorer people who needed good medical service. So I went there. It turned out to be the most fateful decision I ever made,” he said.

Because the hospital was small, he had the freedom to try different specialties rather than focus only on one, and to give full flight to his deep sense of curiosity. Professor Yuen trained as a physician and then a surgeon, even though colleagues and bosses told him he was wasting his time.

“It was actually a blessing in disguise. Patients in all specialties can have infections so it put me in a very good position to manage these patients,” he said.

Six years of regular night shifts took a toll on his health, though. In 1987, Queen Mary Hospital had three openings. He requested applications for all three but fate intervened again and he was only sent one – for clinical microbiologist. That became the jumping point for his hugely successful career. In 1997, he was the first to report that the H5N1 avian virus caused severe symptoms and high mortality in infected patients, then went on to his discoveries on SARS-CoV-1 and then bat SARS-CoV which is highly related to SARS-CoV-2.

Savouring the unpredictable

“I have never stopped doing coronavirus research since 2003. There are lots of SARS-related coronaviruses in bats. Everybody thinks after a pandemic is over, that’s it. Sorry to say it is always the case that another will come back,” he said.

Professor Yuen has repeatedly warned that we should prepare now for the next pandemic to avoid the whole-scale disruptions caused by COVID-19. He has never been afraid to speak out when he sees a need for change, even when it has made life difficult for him at times (he has received numerous death threats).

But the predictability that there will be another pandemic is not the only message of his book. He also wants readers to appreciate the unpredictability of life. “I didn’t really aim for this path, it just happened naturally as time went by. And I love it,” he said.

Professor Yuen decided to put things on paper after the sudden death of his friend, film director Alex Law Kai-yui, in 2022. He wrote the first draft over 14 days, drawing deeply on his memories of old Hong Kong. Professor Ying Chan and Gene Mustain, both retired from HKU’s Journalism and Media Studies Centre, helped develop the draft into a book.

“I’m not young anymore so I felt I should write this before my memories fade. I’m so happy I did because I can feel those good old days. I can still smell the scent of my mother and the warmth of her back when she carried me around. My mother is my strength,” Professor Yuen said.