Yet another covid-19 wave is beginning in Australia, the US and parts of Europe, with some evidence suggesting the BA.4 and BA.5 omicron subvariants are more severe and transmissible than their predecessors
People on a tram in Krakow, Poland, in May
Jakub Porzycki/NurPhoto via Getty Images
Yet another covid-19 wave is beginning in Australia, the US and parts of Europe, among other places. Driven by two omicron subvariants, called BA.4 and BA.5, experts are unsure how bad it will be.
There is some evidence BA.5 in particular may cause more severe disease than its predecessors BA.2 and BA.1, but there is also high covid-19 immunity in most populations.
“All I can safely say is that Australia, the US and UK appear to be on track for BA.5 to …