Member-only story
Variant or ‘Scariant’: When to Worry About Covid Virus Strains
Plus, the most important way to prevent more variants from emerging
Although the word “mutation” often conjures frightening associations, such as three-headed fish or The Andromeda Strain, in reality, mutations are simply changes that arise in DNA or RNA. Reproduction is one opportunity for these changes to emerge, creating the starting material for evolution, including in viruses. In this way, as researcher Nathan D. Grubaugh and colleagues wrote back in March 2020, mutations are just “a humdrum aspect of life for an RNA virus.”
But recent reporting about mutated variants of the SARS-CoV-2 virus has understandably caused some anxiety. When the data don’t confirm reasons to worry, Eric Topol, MD, professor of molecular medicine at Scripps Research, has coined a term for these variants: “scariants.”
But the concerns linger. Why do specific variants make headlines, and how much do you need to worry about them? Here’s what you need to know.
What is a variant and why do they occur?
A variant is a version of the pathogen that contains mutations compared to a reference SARS-CoV-2 virus. The reference virus is typically the most common circulating one, and the variant differs from it but not so much so that it’s a different species, explains Angela Rasmussen, PhD, a virologist at Georgetown University.
Most mutations don’t matter from a human perspective, says Vaughn Cooper, PhD, a microbiologist and molecular geneticist at the University of Pittsburgh. Either the changes don’t affect the coronavirus or they harm it. But viruses with a mutation that gives them an advantage may come to dominate in an individual host. If the mutated version is transmitted to someone else, a variant is born.
Why are so many variants cropping up now?
“When infections are infrequent, there’s not as much opportunity for the virus to evolve,” Cooper says. But then case counts reached millions, so natural selection has a lot of variants to choose from. “It didn’t surprise us at that point that we started to discover them,” says Cooper, because every new infection is an…
