Speaking on a radio show on Saturday, Hung said Hong Kong was now racing against time.
He said the Omicron-driven fifth wave might only peak in early or mid-March, and Hong Kong could see up to 30,000 confirmed cases each day – with actual infections being several times that amount.
The University of Hong Kong professor welcomed government advisors recommending a shorter time interval between the second and third vaccine dose for adults, as well as between the first two BioNTech doses for those aged five to 17.
And he said the interval for minors aged five to 17, who are getting BioNTech, could even be shortened to four weeks, instead of the recommended eight.
Hung also said more could be done to boost vaccination among the elderly, noting that many of the Covid patients, who had died in this wave, had been unvaccinated elderly people living in care homes.
“My recommendation is to make vaccination mandatory, especially for the elderly. Because we need to be fast, and we have already explained that many times,” the expert said.
“The vaccine pass system has almost made vaccination compulsory already, as in if you want to live in an elderly care home, you have to be vaccinated. Therefore we can really consider making vaccination mandatory, to speed up inoculation.”
The HKU expert also backed the government’s decision to start recognising self-test positive results as confirmed cases.
On Friday, health officials said people who test positive for Covid with rapid test kits will no longer need to submit a deep throat saliva sample for confirmation, and that they will soon be able to register their self-test positive result online.
Hung said confirmation via a PCR test was no longer needed as the chance of a fake positive was low.
He said public laboratories were currently overwhelmed, and the new arrangement would alleviate the pressure on them.
Hung said more cases would be discovered, but people with mild or no symptoms could isolate at home, reserving medical resources for the elderly or those with chronic illnesses.