Experts say a new COVID-19 subvariant, nicknamed ‘Centaurus’, could soon add to Australia’s growing coronavirus headache.
Reports have emerged that BA.2.75 is spreading rapidly in India, causing a recent surge in infections and now accounting for 18 per cent of positive test results.
Although the World Health Organisation is yet to officially sound the alarm on the variant, BA.2.75 has reportedly spread to seven countries, including Australia.
Professor Catherine Bennett, Deakin University chair of epidemiology, told The New Daily that while it is difficult to predict whether this will become the dominant variant, it is likely to add to Australia’s growing “ocean” of circulating COVID strains.
What do we know so far?
BA.2.75 is an evolution of BA.2, a highly infectious Omicron subvariant, often referred to as the ‘stealth’ variant.
The subvariant reportedly contains new mutations in the spike protein that would enable it to evade antibodies (either from vaccination or previous infection).
The new subvariant has quickly spread to countries including Japan, Germany, the United Kingdom, Canada, the United States and New Zealand.
Is BA.2.75 more dangerous?
With little information available about the new strain, it’s difficult to decipher whether BA.2.75 will be more dangerous than its predecessors.
“Surveillance-minded folks – worth keeping a close eye on BA.2.75 – lots of spike mutations, probable second-generation variant, apparent rapid growth and wide geographical spread,” virologist Tom Peacock from Imperial College London tweeted late last week.
“None of these individually really flag as that worrying but all appearing together at once is another matter.”
It could take months to fully comprehend the subvariant’s severity, as it did with the BA.4 and BA.5 variants currently spreading around Australia.
BA.4 and BA.5 were first identified in January and February, but they took months to gain ground and are only now starting to wreak havoc.
Although they accounted for a combined 5 per cent of infections in April, they now make up 40 per cent of total infections.
Professor Bennett said case numbers no longer provide sufficient insight alone. She said the death rate was likely to be the best indication of the subvariant’s severity.
“[We saw] the average number of deaths being reported every day go up by 50 per cent [with BA.4]. So we’ve been up from around 10 to 15 deaths a day, and we’ve stayed there ever since,” she said.
“So we’re not seeing skyrocketing numbers. But it is a concern if it translates to an increase in deaths.”
As of Tuesday, 3740 people in Australia are in hospital with COVID-19, according to COVID Live.
State and federal governments are urging eligible Australians to come forward for their second booster shot to slow the spread of the virus in the community.
Should we be bracing for an ‘Omicron wave 2.0’?
Although the subvariant could eventually cause COVID-19 cases to rise, Professor Bennett said the variant is unlikely to prompt another Omicron-like “tsunami” of cases for Australia.
However, it could add to the country’s growing “ocean” of subvariants, with the BA.4 and BA.5 strains still lingering.
“We haven’t really come off any of our waves. Because we’re in winter, the numbers are still high,” Professor Bennett said.
“For us, it’s waves in deep water. The peak doesn’t look as high because the case numbers haven’t really gone down as much.”
Professor Bennett said time will tell just how troublesome this new subvariant proves to be in Australia.
“You’d have to sort of see [the variants] head to head in the same population to know if BA.2.75 … would replace the others. We might just end up with a few strains circulating at the same time.”
The subvariant has quickly earned itself an unofficial nickname, thanks to one bold Twitter user.
BA.2.75 quickly earned the nickname ‘Centaurus’ online, with one Twitter user proclaiming they wanted to name the new strain after the Centaurus constellation.
However, the nickname likely will not stick.
In May 2021, the WHO announced it would be using letters of the Greek alphabet to name all future COVID strains.
It had previously named them after the locations where they were first detected but reverted to Greek names to reduce stigma.
The WHO named the current major strains, Delta and Omicron, after it declared they were ‘variants of concern’.
But it has not yet declared BA.2.75 a ‘variant of concern’ and so has not given it a Greek name.