Delta variant requires higher herd immunity, dep health minister says

The previously-estimated minimum coronavirus herd immunity level at just over 60 percent of the population is no longer valid with the new Delta mutation of the virus, a Polish deputy health minister has said. "According to experts, the Delta mutation now requires (herd) immunity at around 85-90 percent of the population, which is very high," Waldemar Kraska told Polish public radio PR24 on Wednesday. "We still have a lot to do," he added.