Lee was responding to a reporter who cited concerns from observers and online users over an incident last month. Protesters against what could be one of the country’s biggest financial scandals in the Chinese province of Henan had found that the health codes on their phones required for public transport or entry to buildings had been disabled, flagging them as a Covid-19 risk.

Over the weekend, Hong Kong Secretary for Health Lo Chung-mau suggested introducing a real-name registration system for the government’s “Leave Home Safe” risk-exposure app, under the vaccine pass scheme required for entry into premises such as restaurants and entertainment venues.

Lo said the system would have colour codes to identify patients and high-risk individuals, with red denoting a positive Covid-19 result and yellow representing an active quarantine status for arrivals, both of which would deny users entry into “high-risk” venues.

He also said the government was considering plans to allow arrivals to spend part of their hotel quarantine at home.

Hong Kong to step up enforcement of Covid restrictions with colour-coded app

Lee on Tuesday said the proposed health code would only target two types of people, meaning the system was “very specific” and only involved “small numbers”.

“We are thinking of designing methods that will … allow us to react more quickly [and] to respond more precisely, and at the same time, allow more people [to be less restrictive] in their activities so that normal business can go about and the economy can go about in a much-relaxed way.”

Daily infections in the city have more than tripled in the past 30 days, hitting 2,863 on Monday, including 252 imported cases. Seven additional deaths were also reported. Hong Kong’s overall Covid-19 tally stands at 1,273,663 cases, with 9,419 related fatalities.

Hong Kong experts warn wristbands to track Covid-19 patients not foolproof

The chief executive said the city needed to “face the reality” of rising pandemic figures.

“We can see the figure escalating, already now it averages about 3,000 … The trend indicates that the figures will go up very quickly as well,” Lee said, pointing out that the number of Covid-19 patients in hospital had increased from more than 300 to beyond 900 in 1½ months.

In light of such developments, Lee said authorities must ensure what happened during the fifth wave would not be repeated.

“We have to ensure the safety of people with high risk such as the elderly, young children … those who suffer from long-term diseases, and also those who are exposed to high risks such as people in the medical profession,” he said, warning that the city had to prevent its medical system from becoming overwhelmed.

How Hong Kong’s new health code system for Covid cases will affect residents

Lee pledged the government would try to “be scientific and precise” so that vulnerable groups could be protected, while international travellers could come in and out of Hong Kong conveniently.

“That’s why we are trying to reduce the number of days of isolation in hotels so that they can go about their normal activities,” he added.

But he did not respond to a reporter’s question on whether the government would scrap hotel quarantine if the yellow code was introduced to restrict people in quarantine from entering high-risk premises.

Lee’s predecessor Carrie Lam Cheng Yuet-ngor had consulted an expert advisory panel on pandemic matters. Members of the panel included University of Hong Kong experts Yuen Kwok-yung and Gabriel Leung, as well as Chinese University’s David Hui Shu-cheong.

Asked if he and Lo had also consulted experts before making decisions, Lee said he had been seeking consultation and an official advisory committee would be appointed soon.

Hongkongers using Shenzhen Bay Port crossing can soon book Covid-19 tests online

A medical expert and a lawmaker expressed doubts on a radio programme over the planned health code’s effectiveness.

Legislator Michael Tien Puk-sun cited the experience of Macau, which had a similar health code in place. The casino hub was still hit by an outbreak that triggered a week-long lockdown.

“When the ‘Leave Home Safe’ app already operates on a real-name basis, what high-risk venues are still not covered by the vaccine pass? I can’t think of any, but if there are, the government should just expand vaccine pass coverage,” he added.

Tien said the new arrangements gave the impression that the government was just transplanting the mainland practice into the city.

He suggested an alternative of temporarily disabling the vaccine passes of high-risk users until they complete quarantine, since their names were already on record as being in isolation and therefore they would be barred from entry to premises.

Microbiologist Dr Ho Pak-leung told the same radio show that he did not understand the proposed effectiveness of the health code policy.

“Mobilising manpower for the health code will inevitably slow down the speed of distributing Covid-19 medicine and encouraging vaccination,” Ho cautioned. “We are talking about the need for speedy action. We need to be quick on vaccinating the elderly, offering door-to-door BioNTech jabs and conducting polymerase chain reaction tests for such residents so they can get Covid-19 pills as soon as possible.”