All Hongkongers should expect to get a booster jab, respiratory disease expert David Hui Shu-cheong said, as a joint research by two Hong Kong universities showed that the Covid-19 variant Omicron significantly reduces the effect of BioNTech vaccines.
Back in November, the government started allowing those who received Sinovac jabs to get a third dose to boost their antibody levels against Covid
-19. Those with weak immune systems and chronic diseases can also get booster jabs, regardless of the type of vaccine
But the Omicron variant might make it necessary for all residents to get an extra dose, Hui said on a radio program on Sunday.
A scientific committee under the Department of Health will have a meeting on December 23, during which experts will discuss whether to expand the availability of third jabs to more groups.
On Sunday, a study jointly conducted by the LKS Faculty of Medicine of The University of Hong Kong and the Faculty of Medicine of The Chinese University of Hong Kong has revealed that Omicron can significantly reduce the virus killing ability of the BioNTech vaccine
by 32 times or more. Results were published recently in the journal Respirology.
Professor Malik Peiris, Professor of Virology at HKU, and his team isolated the Omicron variant earlier. They carried out tests to measure antibodies generated by BioNTech
against the Omicron variant and the original SARS-CoV-2 virus.
In the recent initial experiments on Omicron variant, the blood of 10 people vaccinated with two doses of the BioNTech vaccine
was tested against the original SARS-CoV-2 virus from 2020 and the Omicron variant that HKU isolated from the first Hong Kong case.
The blood tested was collected one month after the second dose of the vaccine
, the time when the highest level of virus-killing antibodies in the blood is expected.
"We can see that most individuals had high levels of virus killing (neutralisation) activity against the original SARS-CoV-2 but this ability was markedly reduced by 32 folds or more against the Omicron variant," said Peiris.
He added that these findings suggest that vaccine
protection against breakthrough infection with Omicron will be much reduced.
A similar test of another vaccine
used in Hong Kong, Sinovac, is being conducted and the results will soon be available. Because previous studies suggested that virus-killing antibody levels in Sinovac vaccines
are lower than the BioNTech vaccines
, its ability to fend off the Omicron variant is expected to be largely reduced as well.