Microscopic view of the COVID-19 virus.

BA.2 does not cause more severe illness than BA.1

By Kelly April Tyrrell, UW–Madison

In a study published in Nature on May 16, a research team led by University of Wisconsin–Madison virologist Yoshihiro Kawaoka and colleagues in Japan show that the BA.2 subvariant of omicron is similar to BA.1 in both the severity of illness it causes and in its ability to cause infection.

Omicron is now the dominant version of the virus that causes COVID-19 worldwide and BA.2 is the dominant subvariant in nearly seven dozen countries.

The peer-reviewed findings contrast with a recent study from another research team that relied on recombinant virus bearing spike proteins from BA.1 and BA.2. Read more …