Why Are COVID Variants Named With Greek Letters?

Here's why some Greek letters are used to name new variants, why some are skipped and what happens when we reach the end of the alphabet.
Scientists are doing their best to name new coronavirus variants in a way that makes sense to the general public.
Aitor Diago via Getty Images
Scientists are doing their best to name new coronavirus variants in a way that makes sense to the general public.

When COVID-19 variants first started popping up, experts often described them based on where they were first discovered as a way to differentiate them from the original strain. But, as we quickly learned, the coronavirus continued to mutate into new versions ― bringing a need for a new system for naming them.

So why the switch to the Greek alphabet? Below is a brief breakdown on why Greek letters are used, why some are skipped, and what happens when we reach the end of the Greek alphabet (and why you should get vaccinated so that we please, please don’t).

Why each COVID variant has its own letter

Let’s start with why we need to distinguish these different versions of COVID-19 at all. Viruses are living organisms and evolve like other living organisms. In fact, a committee exists for categorizing and creating a taxonomy of viruses: the International Committee on Taxonomy of Viruses, or ICTV.

The ICTV is charged with developing the ways “in which we classify organisms, and we group them together according to similar properties,” according to Elliot J. Lefkowitz, the data secretary for ICTV.

Usually, these classifications contain a mix of numbers and letters. (You may have seen some of them, like B.1.1.7, during the pandemic. SARS-CoV-2, the virus that causes COVID-19, is also part of these classifications.)

This is where the Greek letter process comes in. Since SARS-CoV-2 is highly contagious and can mutate many times, scientists have had to categorize a number of new variants. But, as the World Health Organization notes, it gets cumbersome referring to a variant by its scientific name.

There are really only a handful of different viruses with developing lineages that have unique properties that cause widespread disease, according to Lefkowitz.

“And of all the ones I can recall, I don’t recall any others that use the Greek letter convention,” he added.

In essence, we’re blazing new trails with the COVID-19 variants.

For a brief time, we described variants based on where they were first discovered, such as the “U.K. variant” or the “South Africa variant.” But that led to another issue: Labels that associate variants with their locations of discovery can create stigma and lead to discrimination toward those regions, the WHO stated.

Why some Greek letters are skipped when naming coronavirus variants

Although we’re moving through the Greek alphabet, well, alphabetically for the COVID variants, scientists have skipped some letters in the process.

In some cases, the variant was merely one of interest (meaning it was notable and increasing in rate, but not necessarily as widespread or severe as others) instead of a variant of concern. So while those variants were named, they just didn’t gain enough traction to become common knowledge. This was the case for variants like lambda and mu.

Two letters were recently skipped entirely to get us to omicron: nu and xi. This was because “nu is too easily confounded with ‘new,’ and xi was not used because it is a common surname,” the WHO said in a statement.

What happens when we get to the end of the Greek alphabet

For those who live in areas affected by hurricanes, you’re probably familiar with what happens during an active season: Once the end of the named hurricane list is reached for the year, scientists move on to the Greek alphabet.

So what happens once we reach the end of the alphabet? Previous viruses that used Greek letters started putting prefix letters before new strains when the time came, Lefkowitz said. He believes this is the route we’ll go with coronavirus variants if necessary. Time will tell. There’s still a lot we don’t know about COVID, despite the fact that we’ve been living with it for almost two years. That includes how we name new variants.

“I think an important fact that maybe is not emphasized enough is that we never followed any other virus disease as closely as we’ve been able to follow COVID-19,” Lefkowitz said. “And so it’s required scientists to think about new ways of approaching how we communicate the information, and how we take this level of detail and make it understandable to ourselves and to the general public.”

Of course, the best way to make sure we don’t actually reach the end of the Greek alphabet is to protect ourselves and others from the virus in the first place. A virus will continue to mutate as long as it has hosts to attach itself to. If we get vaccinated, wear our face masks and keep following other basic health measures, we’ll reduce the chances of us blowing through the list.

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