More information about Omicron needed before S'pore decides if Covid-19 rules should change: Experts

Omicron is the fifth variant of concern that has emerged since the pandemic first gripped the world almost two years ago. ST PHOTO: DESMOND WEE

SINGAPORE - The new coronavirus variant Omicron has put the world in a state of high alert, but two experts The Straits Times spoke to on Saturday (Nov 27) say more information is needed to determine if current pandemic protocols should change.

For instance, it is not yet clear if current vaccines can protect a person from falling ill after being infected by the Omicron variant, said Professor Teo Yik Ying, dean of the Saw Swee Hock School of Public Health at the National University of Singapore.

Other things to monitor would be how fast the new variant spreads, and whether those infected would suffer a more severe form of Covid-19.

Prof Teo said: "If the variant increases transmissibility, but does not increase the risk of disease and death beyond what is already observed in the Delta variant, then the impact on the healthcare system is not that large if countries are able to ensure a high uptake of vaccination and vaccine boosters."

But he added that if there is clear evidence that Omicron increases the risk of disease and death even for the vaccinated, then countries will need to review the relevance of endemic Covid-19 strategies.

"At the moment, it is still too early to determine whether the outlook is going to be pessimistic or optimistic," he said.

Professor Hsu Li Yang, who is vice-dean of global health and programme leader of infectious diseases at the Saw Swee Hock School of Public Health, said the worst case scenario is that the Omicron variant is more transmissible than the Delta variant, and that it can also completely evade the immune response triggered by past infection or vaccination.

If this happens, Singapore would have to abandon its approach to treating Covid-19 as an endemic disease, until new vaccines become available.

He added: "But I think this scenario is very unlikely, given that it is not a completely new virus."

The new variant was first identified in Gauteng, a province of South Africa, and the World Health Organisation (WHO) was alerted on Wednesday (Nov 24).

It was declared a variant of concern by the WHO on Friday (Nov 26) because of the large number of mutations detected in its spike protein, which may cause an increased risk of reinfection, among other negative effects. The spike protein is what the coronavirus uses to begin infecting human cells.

It is the fifth variant of concern that has emerged since the pandemic first gripped the world almost two years ago. The highly transmissible Delta variant was declared a variant of concern in 2021.

To curb Omicron infections, nations around the world have moved quickly to stop global transmission of the variant, ceasing flights from many countries in the continent.

On Friday (Nov 26), Singapore's Ministry of Health announced that all travellers with recent travel history to seven countries in Africa, including South Africa, Namibia and Zimbabwe, will be barred from entering Singapore from 11.59pm on Saturday (Nov 27).

Of the 27 countries that the Republic has quarantine-free travel schemes with, Britain, Germany and Italy have detected the Omicron variant.

Asked if the variant could affect these vaccinated travel lanes (VTLs), Prof Teo said it depends on factors such as the virus' incubation period - which refers to the number of days between when a person is infected and when symptoms start to show - and the length of the infectious period.

He explained: "This will help to determine whether the existing testing requirements for travellers on the VTLs will result in a higher rate of leakage."

Singapore will be barring all travellers with recent travel history to seven countries in Africa from 11.59pm on Nov 27, 2021. ST PHOTO: JASON QUAH

Current border protocols have kept this leakage - referring to the number of travellers infected with Covid-19 - at one infected per thousand travellers, he said.

Both experts said that country-specific border restrictions merely delay the arrival of the variant into Singapore.

Prof Hsu said: " It is highly likely that the Omicron variant is already present and circulating in other non-African countries that have direct flight connections with Africa and Singapore."

He noted that in one case of Omicron infection in Belgium, the patient had neither set foot in South Africa nor the other six countries commonly listed in the new travel bans.

"Therefore, unless the situation changes, we are likely to have persons infected by this new variant on our shores within a matter of weeks."

Correction note: This story has been updated for accuracy.

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