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The TLDR: A new variant detected in South Africa has a dizzying number of mutations—and is being described as “horrific” by some experts. But we still don’t know enough about this version to figure out how it behaves. Here’s what we know so far.
A quick guide to variants
What are variants: A ‘mutation’ is different from a ‘variant’—which in turn is different from a ‘strain’, and here’s how:
- This coronavirus—Sars-Cov-2—is a strain of a larger family of coronaviruses, which includes other strains such as Middle East respiratory syndrome (MERS) that caused severe respiratory illnesses in the past.
- Now, viruses spread by replicating themselves at an astonishing speed.
- So when a virus produces a copy of itself, there are routine changes and sometimes ‘copying errors’—and that may cause changes in a protein molecule's behaviour.
- These ‘errors’ can make a virus weaker, more harmful—or have no effect at all. The changes are called ‘mutations’.
- When a virus undergoes significant types of mutations that causes it to behave differently from the original virus, then it becomes a variant.
Why we have new variants: The longer the pandemic stretches, the more opportunities the virus has to keep replicating itself. As infections spread, variants typically evolve in immuno-compromised patients who are ill over a long period of time, as The Atlantic explains:
“The variants may have evolved in immunocompromised patients who were infected with the virus for months. Normally… ‘your immune system is going to town on it. It’s really trying to beat it up.’ But immunocompromised patients mount weaker immune responses. ‘It becomes almost like a training course for how to live with the human immune system,’ she says. That may be why these variants have so many new mutations at once, as if a year or two of evolution has been compressed into months. This is probably quite rare, but with tens of millions of infections around the globe, rare things will show up.”
Variants of concern: Not all variants are a cause of worry. Scientists only pay attention when a variant shows that it is more infectious or more likely to cause severe disease. These are called ‘variants of concern’—and there are four right now: Alpha, Beta, Gamma and Delta.
Ok, tell me about this new variant…
The name: It is called B.1.1529, but will likely receive a Greek name like the others soon. The variant likely evolved during a chronic infection of an immuno-compromised person, possibly in an untreated HIV/AIDS patient.
The location: The variant was first spotted in Botswana, where three cases have now been sequenced. It was also spotted in one case in Hong Kong—in a traveller returning from South Africa. The most cases have been detected in South Africa—but the reporting varies wildly on the exact number. Euro News says there are 22 confirmed cases. Reuters cites “100 specimens,” while BBC News puts the number at 77. But they all agree that the spread is the heaviest in the province of Gauteng—where it accounts for 90% of the cases. And scientists say it “may already be present in most provinces" in the country.
The mutations: The variant has 50 mutations in total—of which 32 are in its spike protein. Any changes in the spike protein are worrying because that’s the part of the virus targeted by vaccines—to block the virus from entering the human cell. And of these 32 changes, 10 are in the exact bit—“receptor binding domain”—that helps the virus attach itself to the cell. In comparison, the highly infectious Delta variant has only two mutations in this location.
Umm, that sounds worrying…
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