Booster 'a must' for BioNTech takers in Omicron fight

All Hongkongers should get a booster jab, government adviser David Hui Shu-cheong says, as joint research by two universities shows Omicron reduces the antibodies of a person who has had two BioNTech shots by 97 percent.

Hui said the study - made by Chinese University and University of Hong Kong - showed that Omicron can significantly reduce the virus-killing ability of the BioNTech vaccine by 32 times or more.

He believed the antibodies will be even less for Sinovac takers.

Despite that, Hui said the vaccines are still effective in protecting recipients from developing serious complications and death after contracting Omicron.

Omicron, which has spread to at least 57 countries, is more contagious than the Delta variant but it does not lead to a high death rate, health experts say.

Hui said a third BioNTech vaccine could boost the antibody level and protect people from Omicron.

"Pharmaceutical company Pfizer's statistics have shown that the antibody level after receiving the third shot is 25 times higher than after just two shots," Hui said.

"Other studies also showed that three doses of BioNTech vaccine have a 75 percent protective rate against Omicron."

For the joint research, the two universities collected the blood of 10 people who had two doses of BioNTech and used it to test against the original coronavirus from 2020 and the new variant.

The blood samples were 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, researchers said.

They found that the blood samples had 320 units of antibodies after infection with the original virus, while there were only 10 units of antibodies left after infection with Omicron - a 97 percent drop.

"We can see that most individuals had high levels of virus-killing ability against the original [virus] but this was markedly reduced by 32-fold or more against Omicron," HKU virologist professor Malik Peiris said.

The universities are also conducting tests with the Sinovac jab and said the results will be available soon.

"Previous studies suggested that virus-killing antibody levels in [Sinovac] vaccines were lower than that with the BioNTech vaccines," researchers said.

The research team will also test the blood of those who get booster shots.

Secretary for Food and Health Sophia Chan Siu-chee said experts will meet on December 23 to discuss extending inoculation of the booster jab for nonpriority groups who have taken two BioNTech doses.

She called on the public to take the boosters as soon as possible and not to wait until authorities extend "vaccine bubble" arrangements.

Hong Kong yesterday recorded five imported cases from the United Kingdom and the Philippines, taking the city's tally to 12,489 cases with 213 deaths. Two cases had the L452R mutation present in Delta.

wallis.wang@singtaonewscorp.com