Dr Jasper Chan said experiments on human tissue and mice showed Omicron replicates with a much lower efficiency and causes less damage than the original strain of Covid-19 and earlier variants such as Delta.
But Omicron can still cause more serious complications and kill more vulnerable people than the common cold, he warned.
“If you look at the clinical data from susceptible groups in terms of severe diseases and deaths, Omicron is still much higher. So I do not think that we can say that it has now evolved into just a common cold virus… not yet,” he said.
Chan said Hong Kong must boost its vaccine take-up, especially among elderly people, before considering “living with the virus”.
However, he said he is hopeful that the coronavirus will continue to grow weaker, signalling an end to the pandemic.
“There’s some hope because we can see that it is along this trajectory of evolution so it’s now getting milder,” he said.
“It’s more adaptable to human-to-human transmission. The virus is very smart and it will be able to live among humans while not killing us. That is eventually what is probably going to be achieved, but at this stage not yet.”