New versions of coronavirus that spread faster and might evade the immune system are causing fears about vaccine efficacy and a rise in covid-19 deaths. Here’s what you need to know

By Graham Lawton
Illustration of the B.1.1.7 coronavirus variants spike protein (red)
Juan Gaertner/Science Photo Library
THE rise and spread of new variants of the coronavirus are seen as ushering in a dangerous new phase of the covid-19 pandemic. But from the virus’s perspective, nothing has changed. It is just doing what comes naturally to viruses: evolving.
It is now well-established that SARS-CoV-2 is a coronavirus with a large and unusually stable RNA genome, but that doesn’t mean it doesn’t change at all. Unlike most other RNA viruses, which are among the most mutation-prone biological entities in the world, SARS-CoV-2’s genome changes very slowly. This is largely …