Variations on a deadly theme: How COVID-19 is changing

Within months of the first reports of pneumonia caused by a previously unknown virus emerging from Wuhan, town centres across the UK became eerily deserted, millions faced delayed and cancelled NHS treatment and the national debt reached levels not seen since the Second World War. Researchers developed vaccines in a remarkably short time. Yet, as soon as SARS-CoV-2 emerged, virologists feared the pathogen would mutate into something worse. Now variants of concern (VOC) from Britain, South Africa and Brazil raise the prospect that SARS CoV-2 would escape the protection offered by vaccines and possibly evolve into a more infectious and deadly strain. This article looks at the biology behind the headlines.