The Latest Understanding of B.1.1.7
Ongoing research is uncovering clues in specific mutations
The spread of the mutated SARS-CoV-2 variant known as B.1.1.7 is worrying because it’s more transmissible. This means that this strain can be spread more easily from one person to the other than the dominant strain. By one estimate, B.1.1.7, which emerged in the U.K., can be up to 70% more transmissible, though several experts agree that 50% is more likely. Though it doesn’t cause more severe disease, its increased transmissibility threatens to cause a rise in new cases and an uptick in deaths, and it may become the dominant variant as soon as March.
As scientists work to understand the new variant, one thing they’re focusing on is what actually makes it more transmissible. The Centers for Disease Control and Prevention (CDC) says that the variant is transmitted more efficiently and rapidly. But what does that say about the virus particle itself? What is it doing differently?
B.1.1.7’s genome carries a total of 23 mutations, 17 of which are in parts of the genome that could cause the virus particle itself to differ in meaningful ways. (Quick refresher: A genome carries instructions for making the proteins that ultimately make up the virus.) As Kai Kupferschmidt wrote in a thorough overview of the new variant’s mutations in Science…
