Did a Random Person on Twitter Name the Latest COVID Variant ‘Centaurus’?

A new subvariant is all the rage, but where did the name come from?
Image: Getty Images

People have taken to calling the new coronavirus variant “Centaurus,” a reference to a distant galaxy and the father of the centaurs from Greek myth. It’s a catchy name for a variant of covid that appears highly transmissible and seems to be supplanting other variants. It’s also not an official name. Rather, some random guy on Twitter who tweets about COVID chose it and it seems to have caught on.


Xabier Ostale is not a virologist. He’s a person on Twitter who shares information about Covid, its various strains, and ways to keep yourself safe. The lack of qualifications didn't matter though, the name “Centaurus” caught on. In the last few days, stories from The Guardian, Deseret News, Fortune, and others have written about the Centaurus subvariant using Ostale’s nickname.

Ostale does, indeed, seem to have coined the name. The BA 2.75, what he called Centaurus, first appeared in India in May of 2022. A search of Twitter in the months of May and June revealed that anyone using “centaurus” were mostly talking about the distant galaxy. After July 1, when Ostale named the variant, all references to Centaurus point back to Covid. Google Trends shows a similar explosion of people searching the term after July 1.


When asked how he came up with the name, Ostale told Motherboard that he named it “After the galaxy Centaurus A, in the Centaurus constellation. I think the Greek alphabet is not the adequate choice. Galaxies are many, and with catchy names.”

Centaurus is, technically, a subvariant of Omicron with the official designation of BA 2.75. The reason it doesn’t have an “official” name is because the WHO doesn’t give out fancy titles to subvariant mutations of strains it's already named.

The WHO told Motherboard it’s watching BA 2.75, but it’s still too early to name it. “The variant is a sublineage of Omicron and has some additional mutations, including in key regions of the spike protein, which need to be studied,” it said. “We don’t have enough information yet on the impact it has on disease severity. We will be closely following the evidence as it comes in.”

They’ve currently listed it as a Virus of Interest under the umbrella of Omicron. “However, if this variant behaves very differently from Omicron AND is shown to have a public health impact, we would consider assigning it a Greek name and calling it a new variant of concern,” the WHO said.

The WHO’s web page gives more details about how it names variants. “To assist with public discussions of variants, WHO convened a group of scientists from the WHO Virus Evolution Working Group, the WHO COVID-19 reference laboratory network, representatives from GISAID, Nextstrain, Pango and additional experts in virological, microbial nomenclature and communication from several countries and agencies to consider easy-to-pronounce and non-stigmatising labels for [viruses of interest ] and [viruses of concern],” it said on its website


“At the present time, this expert group convened by WHO has recommended using letters of the Greek Alphabet, i.e: Alpha, Beta, Gamma, Delta which will be easier and more practical to be discussed by non-scientific audiences,” the WHO’s blog explained.

But that’s not quite good enough for Ostale, who explained why he picked a nickname for the variant in a Twitter thread. “Why to name or nickname variants of sars2? It’s simple. 

It's simple. People will understand much better nicknames than letters and numbers, their perception of the different subvariants is a mess,” he said. “WHO isn't doing what they should do, name the variants and sublineages that are spreading more. For people to get it. They want people to not get it, to get confused, to think it's still omicron=mild and so on.”

According to Ostale, people hear about BA 2.75, a subvariant of Omicron, and they believe it’s the same mild strain they’ve already heard about. Give it a new name though, call it Centaurus, and people might just pay attention.

“BA.2.75 is Centaurus,” he said on Twitter. “Centaurus is very transmissible, and it sucks. It's already surging in many countries. It sucks. Do wear a mask and avoid crowds.”