'Herd Immunity Harder To Reach With Sinovac's Use'

The head of a pharmacists' group said more people in Hong Kong need to be vaccinated against Covid-19 to receive herd immunity, given the low efficacy rate of the Sinovac vaccine.

One day after recommending the jabs for emergency use in Hong Kong, the convenor of the expert panel, Wallace Lau, told an RTHK programme that the Sinovac vaccine could help the local population achieve herd immunity despite an overall efficacy rate of just over 50 percent.

The panel gave a unanimous recommendation after data they received from the mainland drug maker suggested that the jabs have an overall efficacy rate of 50.66 percent among people between 18 and 60 years old. The efficacy rate increased to 62.3 percent when two doses are administered 28 days apart.

But William Chui, president of the Society of Hospital Pharmacists, warned that with the relatively low efficacy rate, Hong Kong might not be able to achieve herd immunity even when 70 percent of its people are inoculated against coronavirus.

"Maybe we need 80 percent of the people to be vaccinated, or even more [for Hong Kong to reach herd immunity]. When the vaccine efficacy rate is relatively low, it's all the more important for more people to get vaccinated," he said.

The only vaccine approved for use in Hong Kong so far, developed by German firm BioNTech, has an efficacy rate of more than 90 percent.

Chui said while the Sinovac vaccine may be less effective compared with the BioNTech jabs, it's also less likely for recipients to experience side effects.

He also said he backed experts' move in recommending the Sinovac jabs, even though the World Health Organisation has yet to approve it and the government here exempted Sinovac from having to publish clinical data in medical journals.

He said Hong Kong might not be able to wait longer for data to be published in medical journals, and having experienced experts review the data would be sufficient.

Lau, meanwhile, again defended the decision to endorse the Sinovac vaccine, dismissing suggestions that the panel had lowered its threshold for vetting the jab.

The panel convenor insisted the vetting process was stringent, saying the review was done by 12 experts compared with five people who review the data for medical journals typically.