But despite the comparatively higher number of people receiving booster shots, local experts said the overall progress of the city’s vaccination drive was unsatisfactory, particularly among the elderly, who are at greater risk of severe illness.

Hong Kong logs 14 new Covid-19 cases; 2-week ban for Cathay Toronto, LA routes

“My main concern is about the low inoculation rate among the elderly, especially those aged 80 or above. If they get infected, the outbreak will be explosive. This is really worrisome,” said respiratory medicine expert Dr Leung Chi-chiu, noting the demand for booster shots might be driven by concerns over the relatively low efficacy of the Sinovac vaccine compared to BioNTech.

“If there is a fifth wave outbreak, the health care system will be greatly impacted.”

To date, about 72 per cent of the city’s total population has received at least one jab, while 69 per cent have taken two. But the inoculation rate among the elderly has remained stubbornly low, at about 20 per cent for those aged 80 and above, and 48 per cent for those aged between 70 and 79.

Leung urged the government to devise an emergency plan to persuade unvaccinated, elderly Hongkongers to get their jabs in the event of a fifth wave, including by sending outreach teams to community and elderly care homes.

“The government must carry out a vaccination mop-up programme within two weeks once the fifth wave hits Hong Kong,” he said.

So far, booster shots have only been available to high-risk groups – including the elderly and those with weak immune systems, such as cancer patients and organ transplant recipients – and to those who previously got two doses of the mainland China-produced Sinovac vaccine. Booster shots will become available to those who had received two doses of the BioNTech vaccine starting on January 1.

But Leung and fellow expert Professor David Hui Shu-cheong warned that given the looming threat of the more transmissible Omicron variant, the unvaccinated would be susceptible to another outbreak, posing a grave threat to the city’s health care system.

Hui, a respiratory medicine expert from Chinese University, agreed that the city’s vaccination figures were underwhelming.

“Singapore’s overall vaccination rate has already hit over 83 per cent,” he said. “With this slow pace in Hong Kong, if the fifth wave of the pandemic strikes, the city’s health care system will easily collapse.”

Hui warned that the elderly were especially vulnerable to infections, especially from the Omicron variant, and were more prone to developing severe symptoms and complications requiring intensive care, and at greater risk of death.

He agreed with previous calls by microbiologist Professor Yuen Kwok-yung for the government to roll out a tough vaccine passport scheme, complete with punitive measures such as barring the unvaccinated from schools and workplaces, to spur residents to get their jabs.

“This is the only way to push up the rate,” Hui said.

Some people receiving their shots in recent days cited a mixture of fear of the new variant and desire to celebrate the Lunar New Year.

Outside the Sai Wan Ho Sports Centre on Tuesday morning, a steady stream of people were showing up to get inoculated with the BioNTech vaccine.

Retiree Yuki Yu, 55, said she was getting her first dose of the vaccine because of the upcoming holiday.

“I didn’t get vaccinated earlier simply because I was procrastinating. But I want to be able to eat the reunion dinner with my family and the Type D restaurants require diners to be vaccinated, so that’s why I decided to get jabbed,” she said.

Her mother, aged 85, also got her first dose of the vaccine recently for the same reason.

For 51-year-old Kumar, his two young children, aged 8 and 10, were the reason he decided to get a booster shot.

“I decided to take a third dose because of Omicron. My two children cannot get vaccinated, so I am getting a booster to protect them,” he said.

When his children become eligible for the vaccine, he will encourage them to get jabbed too, he added.