A New Strain of Coronavirus: What You Should Know

Why did the coronavirus change?
New strains of viruses occur when there is a change (mutation) to the virus’ genes. Ray says it is the nature of RNA viruses such as the coronavirus to evolve and change gradually. “Geographic separation tends to result in genetically distinct strains,” he says.

Mutations in viruses — including the coronavirus causing the COVID-19 pandemic — are neither new nor unexpected. Bollinger explains: “All viruses mutate over time, some more than others. For example, flu viruses change often, which is why doctors recommend that you get a flu shot every year.

“We have already seen multiple variants of the SARS-CoV-2 coronavirus that are different from the version we first saw in China,” he says.

He notes that this particular strain was detected in southeastern England in September 2020. In December, it became the most common version of the coronavirus, accounting for about 60 percent of new COVID-19 cases. The new strain also appeared in Denmark, the Netherlands, and other European countries, and a similar variant emerged in South Africa.