While New Zealand deals with an outbreak of the Omicron BA.5 subvariant of COVID-19, a new strain has also arrived on our shores.
The strain dubbed 'Centaurus' was detected in a traveller from India and officially reported by the Ministry of Health last Tuesday. The strain, which is another Omicron subvariant, is formally known as BA.2.75 and has a large number of mutations.
Centaurus was first reported in India in May and has since spread to multiple other countries including the UK, Australia and, as of last week, New Zealand.
The World Health Organization (WHO) was tracking Centaurus, along with other Omicron subvariants including BA.4, BA.5, BA.2.11.
What's different about Centaurus?
Centaurus differs from other Omicron subvariants because it appears to have multiple mutations outside the spike protein.
Experts have said Centaurus would likely be more transmissible than previous Omicron subvariants, which could be a factor in India's rising case numbers. The country reported 16,906 new infections on Wednesday - up from less than 10,000 daily cases in late June.
In recent weeks, Centaurus has caused the European Centre for Disease Prevention and Control to class the new strain as a "variant under monitoring".
"There are still limited sequences available to analyse but this subvariant seems to have a few mutations on the receptor binding domain of the spike protein," said WHO chief scientist Soumya Swaminathan. "Obviously that's a key part of the virus that attaches itself to the human receptor so we have to watch that.
"It's still too early to know if this subvariant has properties of additional immune invasion or, indeed, of being more clinically severe - we don't know that," Dr Swaminathan said.
However, the number of additional mutations in Centaurus meant the strain was "a potential candidate for what comes after BA.5", Imperial College London virologist Tom Peacock told The Guardian.
"It's hard to predict the effect of that many mutations appearing together - it gives the virus a bit of a 'wildcard' property where the sum of the parts could be worse than the parts individually," Dr Peacock said.
Doctors continued to strongly recommend getting vaccinated and boosted against COVID-19 for maximum protection against emerging variants - including Centaurus.
"Some may say, 'Well, vaccination and boosting hasn't prevented people from getting infected.' And, yes, that is true," said Matthew Binnicker, a Minnesota-based clinical virology director at US health care company the Mayo Clinic.
"But what we have seen is that the rates of people ending up in the hospital and dying have significantly decreased. As more people have been vaccinated, boosted or naturally infected, we are starting to see the background levels of immunity worldwide creep up," Binnicker told AP.
As of Wednesday, 2.69 million New Zealanders had received a COVID-19 booster jab and 3.98 million have had two doses.
Fourth doses were also available for several groups including the elderly and immunocompromised, while boosters specifically designed to fend off Omicron and its subvariants were expected to be available later this year.
"We obviously need to get new boosters in that are more focussed on Omicron," said Michael Baker, an epidemiologist from the University of Otago. "What we do know is that, actually, your risk of serious illness and death is reduced by at least an order of magnitude if you're fully vaccinated and boosted."
