Yesterday (30 Sep 2022), Singapore’s Health Ministry (MOH) reported a 35% to 40% week-on-week increase in COVID-19 daily cases in the past few days.
This translates to 900 to 1,000 more cases every day. “There has been no indication that the increase in cases has led to more severe diseases,” MOH assured.
However, MOH noted that there is an increase in infections by the Omicron variant BA.2.75, which now accounts for about a quarter of all daily infections. MOH said, “It (BA.2.75) is now circulating more widely in our population, due to social mixing and gatherings, and relaxing of masking rules. This is most likely the main reason for the increase in cases.”
MOH added that it expects to see higher numbers of cases over the next few weeks and urged those who have not received their booster shots to do so.
BA.2.75 “Centaurus” Variant Originates From India
The BA.2.75 strain, unofficially named as “Centaurus”, was first detected in India in early May this year. It is a sub-variant of the Omicron variant and has spread to countries like the United States, Britain, Australia, Germany and Canada.
According to a report from the South China Morning Post (27 Sep 2022), the Centaurus strain is showing a worrying ability to evade immunity from vaccination and previous infection. It is said to have two mutations that make it even more adept at locking onto human cells.
Researchers also said that it has an “unprecedented” growth advantage. In a paper published on bioRxiv.org, Chinese researchers said the Centaurus variant exhibited the “most significant ability to escape immunity”.
People previously infected with BA.5 had only a tenth of the ability to prevent reinfection with the new strain than they had against reinfection by BA.5, the paper said. It is also 5.9 times more likely to reinfect people who have been infected with BA.1, 6.2 times more likely to reinfect people who have been infected with BA.2 and 2.7 times more likely to reinfect people who have been infected with BA.5.
In another paper published in the New England Journal of Medicine earlier in September, scientists reported that the Moderna vaccine based on the original type of virus lost four times the ability to neutralise the Centaurus variant.
In Singapore, the first 2 cases infected with BA.2.75 strain were reported in July. Both individuals had recently travelled to India and had “immediately self-isolated” themselves after testing positive, said MOH at the time. And now, less than 3 months later, thousands of “Centaurus” cases have been reported.
Since 29 August, non-fully vaccinated visitors can now enter Singapore freely but are subjected to having to provide result from a COVID-19 Polymerase Chain Reaction (PCR) or professionally-administered Antigen Rapid Test (ART).
They are no longer required to undergo a 7-day Stay Home Notice (SHN) upon arrival. For fully vaccinated visitors, no test is required other than performing a self-declaration.
