The Centre for Health Protection on Wednesday said the government will start to procure the new XBB Covid vaccine, with experts saying it may offer stronger protection against the virus.

David Hui, who chairs the CHP's scientific committee on emerging diseases, said data from Pfizer and Moderna show that their XBB-adapted vaccine can generate a high number of antibodies against the XBB strain, and can also cover strains like EG.5 and BA.2.86.

Chuang Shuk-kwan, head of the CHP's communicable disease branch, said patients were infected with the XBB variant in more than 98 percent of recent local coronavirus cases.

She did not say when the new vaccine would be available, but urged people to get a booster shot beforehand.

The CHP said high-risk groups should get a booster shot if they received their last one, or got infected, more than six months ago.

"Given that there may be limited stock of XBB vaccine even when it is available – because we will reserve [it] for those very high-risk population, such as residents of the elderly homes – so I would urge those high-risk people not to wait until the XBB vaccine is available. They should get vaccination as soon as possible," Chuang said.

The CHP also called on members of vulnerable groups to get flu shots ahead of a possible winter surge.