Mutations in Omicron's spike protein may affect ability to detect and counter it: Singapore

SINGAPORE (The Straits Times/Asia News Network):- The Covid-19 Omicron variant has a large number of gene mutations that has not been reported in a single viral variant before.

So far, scientists have seen 32 mutations out of 5,000 genes on the spike protein, and this gives them reason to believe that Omicron may have fairly different characteristics from the previous Covid-19 variants, Health Minister Ong Ye Kung said in a virtual press conference of the multi-ministry task force tackling Covid-19 here on Tuesday (Nov 30).

Omicron's 32 mutations in the spike protein is about double that of the Delta strain, which now dominates Covid-19 infections around the world.

"This unknown enemy is indeed a lot more transmissible than what Delta is currently. Omicron could spread much more widely than Delta. Whether it will dominate the other variants, just like how Delta had done previously, is a possibility that we need to be alert to and watch out for," Ong said.

The spike protein is an important part of the virus that allows it to bind to human cells and facilitate infection of the cells. So a change in the spike protein may change the ability of the virus to infect cells and cause adverse effects, Singapore's director of medical services Kenneth Mak said at the press conference.

The spike protein is also part of the virus which some diagnostic tests, vaccines and monoclonal antibodies are designed to recognise. Hence, mutations in the spike protein may affect the ability to detect the Omicron variant and counter it, Associate Professor Mak added.

Given the extensive changes in the genetic make-up of the Omicron variant, the task force believes it to be a distinct and separate variant in itself, and not simply an offshoot from other variants of concern (VOC), Prof Mak said.

Omicron was classified the fifth VOC, the fastest any emerging variant has shot to the top of the table. The other four - Alpha, Beta, Gamma and Delta - took between two months and seven months from emergence to being declared a VOC.

This new strain was first reported to the World Health Organization (WHO) from South Africa on Nov 24. WHO said the first known confirmed infection was from a specimen collected on Nov 9. Omicron has also been found in Botswana and Hong Kong.