HONG KONG (BLOOMBERG) - More Hong Kong residents are getting their first shots against Covid-19 as a cluster of Omicron infections grows and an expansion of the vaccine mandate looms.

The city administered more than 7,000 initial injections on both Saturday (Jan 1) and Sunday, the most since the end of November, as residents fear a fresh wave of infections tied to an outbreak at a local restaurant.

Still, the number was surpassed by those getting booster shots as access expanded to all adults on Jan 1, with some 8,000 and 10,600 given on Saturday and Sunday, respectively.

The uptick in immunisation comes as the locally-transmitted cases in the city, the first in almost seven months, heightened the stakes for the vaccine rollout, which is one of the worst among developed economies.

The government is set to launch an expanded vaccine mandate that will require an inoculation in order to patronise restaurants, gyms and cinemas later this month. Only about 65 per cent of Hong Kong's residents have received a first dose because of strong hesitancy, especially among the elderly.

Meanwhile, 5.3 per cent of the 7.4 million-strong population have gotten a booster shot, according to Bloomberg's vaccine tracker.

Another preliminary Covid case has been tied to a cluster of infections at the Moon Palace restaurant, the government said on Sunday.

A woman, the wife of an earlier confirmed patient, had a meal with her husband at the restaurant when a Cathay Pacific Airways Ltd aircrew member who later tested positive was also dining with his family. There have been four other confirmed cases related to Moon Palace.

The government has sent 340 close contacts of the initial patient from the restaurant, and their household contacts, to be isolated at the city's quarantine centre. The group includes 22 restaurant staff members and about 170 customers.

The Omicron threat has delayed Hong Kong's long-negotiated border reopening with the mainland China, which local media had widely reported was expected to begin on a trial basis last month.

While city officials have offered little clarity on the timeline recently, they said they plan to prioritise getting the current Omicron cluster under control.

Hong Kong tightened quarantine requirements for aircrew, which is believed to be the initial loophole that allowed the virus to seep into the city and seed the local transmissions.

The new requirements have dealt a blow to local airlines and further stretched supply chains that were already under strain.