Health workers wear personal protective equipment at a Covid-19 testing center in Hong Kong. Photo: AFP / Anthony /Wallace

The Hong Kong government has been urged to raise its vaccination rate target to over 90% from 70% as the highly infectious Delta variant has made the original herd immunity target unachievable.

Since Hong Kong launched its vaccination program in late February, more than four million people have had their first dose, according to the Health Department. About 60% of people aged over 12 have had their first shot. As of Wednesday, 7.23 million doses had been administered, including 2.71 million Sinovac shots and 4.52 million BioNTech ones.

It is unclear whether Hong Kong can continue to rapidly boost its vaccination rate from September as many workers and elderly people would prefer not to get the jabs until they are mandatory.

Last November, Chief Executive Carrie Lam suggested to Beijing that quarantine-free travel should be allowed between Hong Kong and the mainland. However, the discussion was not pushed forward after the fourth-wave epidemic broke out in Hong Kong in late November.

Early this year, the Hong Kong government adopted the mainland’s “zero local infection” strategy and successfully contained the virus with tough quarantine measures.

In March, Lam proposed the border reopening idea to Beijing again during a meeting with Senior Vice Premier Han Zheng but she was told to boost Hong Kong’s vaccination rate first.

At that time, medical experts said if Hong Kong could have 70% of its population vaccinated in the summer, it would be able achieve herd immunity, which would let the city resume quarantine-free travel with most places.

In June, property developers and large companies launched lucky draw schemes to encourage people to get the vaccines by the end of August while the government ordered frontline civil servants to choose between vaccines and biweekly tests.

A nurse holds her arm after receiving the Sinovac vaccine in Hong Kong. Photo: Peter Parks / AFP

Early in August, the government ordered public sector employees including civil servants, teachers, medical staff and care home workers to either get the jabs or regular tests. This contributed to the 10% growth in the city’s vaccinations over the past few weeks.

Lam said Tuesday that the private sector should follow suit but employers groups said it was hard to force staff to get vaccinated.

Allen Shi Lop-tak, president of The Chinese Manufacturers’ Association of Hong Kong, said the government could consider a ban on unvaccinated people going to public venues but not a policy to force workers in the private sector to choose between vaccines and biweekly tests. Shi said it would be better to lure people to get the jabs with incentives, rather than imposing punishments.

Ho Kai-man, chairman of the Chamber of Security Industry, also said it was difficult to force security guards to choose between vaccines and biweekly tests as many of them were elderly people with three highs – high blood sugar, high cholesterol and high blood pressure – and were unfit to get the jabs. Ho said many security guards could not afford the tests.

While it’s unlikely that Hong Kong’s vaccination rate will reach 70% by August 31, medical experts said even if such a target was achieved, anti-epidemic rules should not be eased, especially when only 24.5% of people over 70 have been vaccinated. Singapore’s overall vaccination rate has reached 80%.

Yuen Kwok-yung, a microbiologist at the University of Hong Kong, said Thursday that the threshold for herd immunity had greatly increased as the Delta variant was transmissible among vaccinated people.

He said herd immunity could have been achieved pre-Delta if 70% of a population were vaccinated with BioNTech jabs which have an efficacy rate of 95%. He said he and his team from the University of Hong Kong found that the threshold increased to 97.4% after new variants emerged.

Taking into account the use of Sinovac jabs which have a lower efficacy rate, the vaccination rate needed for herd immunity would be an unachievable 142.9%, Yuen said, adding that “achieving herd immunity is now like building a castle in the sky.”

The BioNTech Covid-19 vaccine Photo: biontech.de

He added that Hong Kong should maintain its zero-Covid strategy for the time being and only consider easing its anti-epidemic rules several months later. He said people should continue wearing face masks even when the city reached a vaccination rate of 90%.

Ho Pak-leung, an infectious diseases expert from the University of Hong Kong, also said the idea of having 70% of the population vaccinated to achieve herd immunity had been proved wrong as virus transmission remained intense in highly inoculated countries, including Israel, the United States and the United Kingdom. Hong Kong should aim to get all its people vaccinated, he said.

To achieve this, the government could consider a ban on unvaccinated people entering crowded public places, Ho said.

However, respiratory diseases specialist Leung Chi-chiu said such an idea would not work as some people had no confidence in the vaccines.

The problem in Hong Kong was that at the start of the vaccination program, the government had failed to manage a few untoward events that caused a confidence crisis, Leung said. Authorities should think about how they could convince people, especially the elderly, that it’s safe to get the jabs.

Patrick Nip, the Secretary for Civil Service and the official heading the government’s vaccination drive, said Wednesday that 88% of the civil servants in the city had received their first dose but only a quarter of those over 80 were vaccinated. Nip said the vaccination rate of the elderly had to be boosted but he did not elaborate.

Only a quarter of people over 80 in Hong Kong have been vaccinated. Photo: HK Government

Tommy Cheung, a lawmaker representing the Catering functional constituencies seats and an Executive Council member, suggested on Thursday that all teachers should be vaccinated or should be given unpaid leave. In April, Cheung said restaurant staff should be exempt from inoculation if they declared that they were unfit.

Dion Chen, chairman of Hong Kong Direct Subsidy Scheme Schools Council, said it was not necessary to impose mandatory vaccination on teachers as 70% of them had been vaccinated.

Meanwhile, Hong Kong-based foreign companies said they were impatient about the city’s quarantine measures.

“We are of the view that Hong Kong must open itself sooner rather than later or this new quarantine regime could lead many in the international community to question if they want to remain indefinitely trapped in Hong Kong when the rest of the world is moving on,” the European Chamber of Commerce in Hong Kong said in an open letter to Lam on August 19.

“This concern amongst the international business community could pose, undoubtedly, a growing threat to Hong Kong’s status as an international business center. “

The Chamber said Hong Kong should continue to relax all quarantine measures for vaccinated visitors as this will help to reactivate the international business in conjunction with intensive testing efforts. The government has not yet responded to the letter.

Read: HK tightens quarantine rules to fix loopholes