As the Omicron subvariant BA.5 is the latest to take over and dash the hopes of a summer Covid-19 lull, researchers have attempted to quantify and explain its edge over earlier versions of the virus.
The BA.5 subvariant is estimated to be some 70% more transmissible than BA.2, which took over the landscape in the spring, said Trevor Bedford, a computational biologist at the Fred Hutchinson Cancer Center. That estimate is based on how quickly the BA.5 variant displaced its predecessor, he said.