A virus can’t make plans, but it is still driven by one goal: make more viruses. The virus responsible for COVID-19 is no different. Lately, virus offshoots like the strains from the U.K., South Africa, and Brazil have become so good at their goal that they’ve gained international attention, and a handful of similar U.S.-based variants are also emerging. Discover set out to answer some basic questions about them.
First, what a strain is: viruses, including SARS-CoV-2 (the one behind COVID-19), have genetic information that is constantly mutating as viruses make copies of it. New “strains” or “variants” are a mutated version of the SARS-CoV-2 virus that are found in large numbers, and that can also increase more quickly than other versions of the virus, according to Dan Jones. Jones is the vice chair of the Division of Molecular Pathology at Ohio State University's medical school. Jones also led a research team that discovered one of a handful of U.S.-based strains dubbed the “Columbus” strain in January.
Not all multiplying mutated viruses count as a “strain” though, because some mutations may have little to no effect on how the virus behaves. What also defines a strain, but is harder to pin down, Jones says, is that the new group of mutated viruses are “biologically significant or medically significant.” A new strain must work differently in humans than the original strain. And in the case of the U.K., South Africa, and Brazil strains, there is cause for concern because of how fast they spread from person to person. But so far, experts say the tools we use to fight COVID-19 will work for the strains, too.
