Dr Chuang Shuk-kwan, head of the communicable disease branch of the Centre for Health Protection, also revealed two more infections from among those who visited or worked at the K11 Musea shopping centre in Tsim Sha Tsui.

Covid-19 vaccines for Hong Kong: how safe are they, and why is the issue a political hot potato?

Fewer than 10 people had tested preliminary-positive, but at least four of them had untraceable sources of infection.

Chuang said it was too early to tell if the local outbreak had been contained. “There are still day-to-day fluctuations, so we will have to look at a longer trend,” she said.

The new cases took the city’s tally to 11,055, while the death of a 78-year-old man from the coronavirus on Wednesday night brought the death toll to 201 on Thursday.

Secretary for the Civil Service Patrick Nip Tak-kuen, meanwhile, said on Thursday that medical staff at government vaccination centres had advised the 67 residents, some of whom had chronic illnesses or other health concerns, to consult a private doctor before rescheduling their jabs.

A total of 11,700 people on Wednesday received their first dose of the Sinovac vaccine. About 4,300 shots were administered across the city’s five community vaccination centres, and some 6,900 people received their jabs through private doctors.

An expert panel on adverse reactions to vaccines made a preliminary conclusion on Wednesday that the death of a 63-year-old chronically ill man after he received a shot was not directly related to the Sinovac vaccine.

“In the vaccination programme, most cases did not experience any problems … But, unavoidably, there will be certain situations where people have severe adverse reactions, or even death,” Nip, who manages the city’s Covid-19 vaccination scheme, told a radio programme. “We will take each death very seriously, as we are very concerned about this and we hope this does not happen.”

However, infectious diseases expert Dr Leung Chi-chiu said the number of people being turned away was “slightly high”.

“Although there were some concerns about the vaccines as they are new and were developed in such a short time, all of the data so far after so many people have received the jabs shows the risk is low,” Leung said.

He warned that being too cautious in administering vaccines could lead to a delay in the immunisation process. He said for the elderly and those with long-term illnesses, the benefits of receiving the vaccine were still greater than the risks.

“Only if you have seen recent changes in your health, should you consult your doctor before getting the jab, otherwise it should be fine,” he added.

University of Hong Kong Professor Ivan Hung Fan-ngai, co-convenor of the expert committee on vaccine reactions, told the radio show that the patient had died of a heart attack and respiratory failure. “The expert committee, as of now, finds no direct causation between the vaccine and his cause of death.”

However, Hung pointed out that the committee could not fully rule out any indirect links to the vaccine, as experts were still awaiting the full postmortem report, which was expected in two weeks.

The patient, who had a coronary heart disease, high blood sugar and a smoking habit, received the jab on February 26 at Kwun Chung Sports Centre in Jordan. He went to Queen Elizabeth Hospital in Yau Ma Tei on February 28 after suffering shortness of breath and died about 4½ hours later.

Authorities looking into death of chronically ill man two days after receiving Sinovac Covid-19 vaccine

Thursday’s sole untraceable infection was a 69-year-old security guard who lived in Tin Shui Wai and worked in a residential building in Sham Shui Po. Both buildings will be placed under a mandatory testing order.

Chuang said health authorities were still looking into the number of security guards who had shared meals, changing facilities or guard posts with the man, and so far, only one or two others would be classified as close contacts.

She also said that one of Wednesday’s cases, a primary school teacher, had gone to the cinema in K11 Musea, but added it was unlikely she had caught the coronavirus there as authorities believed the source of her infection was possibly related to a family member who tested positive.

However, another worker at a Cartier jewellery store in the mall – who was already in quarantine with several others – was among Thursday’s new infections. Chuang said it was still uncertain how the store’s employees were linked to the cluster of infections from Mr Ming’s Chinese Dining.

“We cannot conclude whether the two cases from Cartier are really linked to the restaurant yet. From the investigation, they had no contact with them. But of course they are in the same mall, they may [have] met each other in the hallway, on the way to work, [when] going out, or even in the toilet, so it’s difficult to conclude,” she said.

That cluster linked to Mr Ming’s has now grown to include 50 people, including nine staff, 22 patrons and their close contacts.

Vaccination drive will continue as expert panel believes man’s death not linked to Sinovac jab

Chuang added that officials might be conducting more environmental tests at K11 Musea after three out of 48 environmental samples previously collected at Mr Ming’s Chinese Dining tested positive for the virus.

All staff at the shopping mall were also expected to undergo a second round of virus screening before the venue reopened on Saturday at the earliest, she said.

Among the four untraceable preliminary-positive infections were a university student, an office worker, a housekeeper and a government worker in the Labour Department.

Meanwhile, a 61-year-old woman was sentenced to 10 days in prison on Thursday for violating a compulsory quarantine order.