The acting premier has warned of a ‘faster running’ virus but experts say there is no clear evidence of shorter incubation period

Medical experts have urged caution regarding claims the Covid-19 variant in Victoria is spreading significantly more quickly, after the acting premier, James Merlino, stated the virus was “running faster than we have ever recorded”.

“The usual transmission is about five to six days [but] in some of these cases, within a day it’s being transmitted,” Merlino said on Thursday as he announced the state’s lockdown would begin on Friday. “The number of cases has doubled in 24 hours. Unless something drastic happens, this will become increasingly uncontrollable.”