Their modeling also predicted that the outbreak will peak in mid-to-late March with 28,000 infections and 468 hospitalizations a day. Nearly 100,000 infected people and a quarter of a million close contacts may be in seven-day isolation at peak.

“In the absence of a city-wide lockdown, the fifth wave is unlikely to be containable even with the current most stringent public health and social measures,” they said in a write-up of their findings. Officials should “urgently consider” the feasibility of a full lockdown, they said.

Mitigation measures are needed to cut transmissions by 85 percent -- a level akin to what Shanghai achieved during its city-wide lockdown in early 2020 -- to get through the outbreak while minimizing deaths, said Gabriel Leung, dean of medicine, and Joseph Wu, who specializes in mathematical and statistical disease modelling at the university. The ultimate number of deaths depends on how long the city sustains the curbs now in place and any changes to them, the researchers said.

Hong Kong will record 954 deaths in the omicron wave by mid-June if the current containment measures remain in place, according to their analysis, which was presented to reporters on Thursday. The data hasn’t yet been peer-reviewed or published.

The deaths toll could surge to 3,000 in a “larger outbreak” or 5,000 in dire circumstances if the rules aren’t maintained, according to two scenarios they detailed using computer modelling. Both involve hospitals coming under significant pressure, and the death toll could rise by another 50 percent to nearly 7,000 if medical centers are overwhelmed, they estimated.

The experts didn’t detail what a full lockdown would entail, and instead said government leaders should adopt the most feasible policies that have the best shot of being embraced by residents. They did say all vaccinations should be directed at elderly residents, testing should be ramped up and people should be warned that they may need to isolate at home so they can prepare.

“Those kind of reactions and behaviors need to last until the number of transmission chains reach such a low level that they can be extinguished,” Leung said. Otherwise, the city would just be “delaying and postponing” the wave of infection and death to come.

They also said there isn’t a public health rationale to quarantine travelers in designated hotels, and they should instead be told to stay at home like local close contacts. Flight bans should also be lifted as local infections now exceed the number of imported cases.

The projections come as Hong Kong recorded three Covid deaths in the ongoing omicron outbreak, after five months without any fatalities. The city’s hospitals are already overwhelmed due to a policy of isolating everyone who’s infected, including asymptomatic people, a practice it’s unlikely to sustain as cases surge.

Even if stricter rules are introduced -- which could slash deaths to an estimated 115 by mid-June -- they would have to stay in place until all the transmission chains in the community are snuffed out, or exponential case growth would return, the researchers said.

Even with the most stringent curbs, the outbreak is expected to linger into May, they found.