Since its emergence in late 2021, Omicron (or BA.1) has quickly become the dominant variant of the COVID-19 virus. The mutations it harboured meant it was more transmissible than the Delta variant, so was able to spread rapidly through populations around the world. It has been found to confer a milder illness than Delta – though milder should not be mistaken for mild.
Scientists are now tracking a subgroup of the Omicron variant, known as BA.2, which was first identified in India and South Africa in late December 2021. Since then, it has been found in the US and Europe. The subvariant is thought to have 20 additional mutations on its spike protein compared with BA.1, though scientists are not quite sure what this will mean for the course of the pandemic. So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than BA.1.
