Why are there so many new Omicron subvariants, like BA.4 and BA.5? Is the virus mutating faster?

The emergence of new variants has raised questions about whether previous infection offers protection and what the future holds

By now, many of us will be familiar with the Omicron variant of Sars-CoV-2, the virus that causes Covid. This variant of concern has changed the course of the pandemic, leading to a dramatic rise in cases around the world.

We are also increasingly hearing about new Omicron subvariants with names such as BA.2, BA.4 and now BA.5. The concern is these subvariants may lead to people becoming reinfected, leading to another rise in cases.