A production line for the Sinovac vaccine in Beijing. Photo: Xinhua

Hong Kong’s medical experts and health officials will hold a meeting to review the clinical data of the vaccine manufactured by mainland company Sinovac to see if it is suitable for use in the city.

Citing results obtained in late-stage clinical trials in Brazil, Sinovac said Wednesday that its coronavirus vaccine, named CoronaVac, had an efficacy rate of 50.38% for very mild cases, which was slightly higher than the World Health Organisation’s minimum requirement of 50%.

It said the efficacy rate reached 77.96% for more serious cases, while that for severe cases was 100%.

The 50.38% efficacy rate was relatively low, but more information about the groups tested was needed to determine whether the Sinovac vaccine was suitable for use in Hong Kong, said David Hui Shu-cheong, chairman of the Department of Medicine and Therapeutics at The Chinese University of Hong Kong.

“We are not certain what these figures are talking about. There are multiple levels of efficacy,” said Leung Chi-chiu, chairman of the Medical Association’s advisory committee. “We need to look at the full data set before we can have a better guess of the actual situation and compare the efficacy between different vaccines.”

“The 50.38% efficacy rate includes patients with mild symptoms and those asymptomatic carriers. So whether the asymptomatic carriers bring down the figures, we don’t know at this point,” said Joseph Tsang, an infectious disease specialist from Hong Kong Medical Association. “We have to get more data from Sinovac in order to interpret as a whole.”

Tsang said he hoped to see more data collected from other countries that have used Sinovac vaccines, rather than only Brazil.

Fears for the elderly

William Chui, the President of the Society of Hospital Pharmacists, said the government should not let elderly people in Hong Kong receive the Sinovac vaccine due to its relatively low efficacy.

“For the elderly, especially those who stay in homes for the elderly, their immune system is not so strong. They may not produce 50% efficacy or even lower,” Chui said. “We advise the government to review the data … There are a lot of choices, at least two – one is AstraZeneca, one is the BioNTech vaccine.”

Chui suggested the elderly receive the BioNTech vaccine, while young and healthy people, who have stronger immune systems, use the Sinovac vaccines instead.

On December 30, the government’s Advisory Panel on Covid-19 Vaccines, chaired by convenor Wallace Lau Chak-sing, the President of the Hong Kong Academy of Medicine, held its first meeting.

The panel was set up in accordance with the Prevention and Control of Disease (Use of Vaccines) Regulation (Cap. 599K), which provides the legal framework for bringing in Covid-19 vaccines that satisfy the criteria of safety, efficacy and quality for emergency use under the present state of a public health emergency. 

The Secretary for the Civil Service, Patrick Nip, one of the officials in charge of the vaccination program to be rolled out in Hong Kong, said the panel would meet soon to review relevant clinical data.

It is expected that Hong Kong people will start receiving vaccinations in mid-February, with shots produced by Sinovac being the first to arrive in the city.

According to a survey by the Faculty of Medicine at the Chinese University of Hong Kong, the overall Covid-19 vaccine acceptance rate for Hong Kong adults was 37%, which is far lower than 70-90%, the level required to achieve herd immunity.

Vials of the CoronaVac vaccine. Photo: AFP/Evrim Aydin/Anadolu Agency

Informed choices

“We think this is rather low and it is well below what we would like to see, which is 70% for some substantial effect on our campaign to fight against Covid,” said Paul Chan, the chairman of the university’s department of microbiology.

“The side effects and the inconvenience perceived by the public are equally strong barriers, and then for the drivers, we find that people really want to understand the severity, the outcome to themselves before they take the vaccine,” Chan added.

Chan urged the government to do more to clear up misunderstandings over coronavirus vaccines to help people make an informed choice. He also suggested that the government could roll out incentives such as issuing vaccination certificates.

The Center for Health Protection said a total of 29 cases, including three imported ones and 29 local infections, were recorded on Wednesday. Of the local cases, 13 had no known source.

One more confirmed infection and a preliminary positive case were reported from the block on 20-26 Reclamation Street in Jordan before residents were evacuated. A total of 27 residents there have contracted the virus so far. New cases were also reported from another block 100 meters away.

“We notice that the pipes of the subdivided flats may not be up to standard. So taking all the factors into consideration, we think that moving the residents to a hotel or a quarantine center may be a safer and quicker way to stop the spread in those buildings,” Chuang Shuk-kwan from the Centre for Health Protection said in a media briefing.

Over the past two weeks, more than 80 Covid cases had been reported in Yau Tsim Mong district, Chuang said, adding that some of the infected were Nepalese who worked at construction sites hit by Covid-19 outbreaks recently. These workers could have spread the virus to their families and friends in the ethnic minority community, she said.

Domestic worker gatherings

Among the imported cases, a 29-year-old Filipino domestic worker was found to be infected. She arrived in Hong Kong on December 24 and moved to her employer’s home at Lai Sum House, Lai Tsui Court in Cheung Sha Wan on January 7. But she then developed a cough and fever and was sent to a hospital. She tested positive on Wednesday.

On Wednesday, Law Chi-kwong, the Secretary for Labour and Welfare, in a written statement rejected suggestions made by lawmaker Elizabeth Quat, who urged the government to forbid foreign domestic workers from gathering in public places during their days off due to public health reasons.

“As regards whether to prohibit domestic workers from gathering in public places, this suggestion itself is quite controversial, and the legislative amendments or mandatory measures involved may even touch upon discrimination issues,” Law said.

The local infection rate of domestic workers was 0.055%, lower than the 0.1% of Hong Kong residents, Law said. It would be unreasonable and unfair to prohibit domestic workers from going out on their days off, he said.

Between December 11 and January 3, a total of 60 fixed penalty notices were issued to domestic workers in public areas in relation to mask and social distancing rules.

Read: China’s vaccine falls short of Western-set standard

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