Illusive herd immunity

The head of the WHO Europe was pessimistic yesterday about vaccines' ability to put an end to the Covid pandemic, as new variants dash hopes of reaching herd immunity.

Faced with the possibility that the virus may be around for many years, health officials must now "anticipate how to gradually adapt our vaccination strategy," in particular on the question of additional doses, Hans Kluge told reporters.

In May, the WHO director had said "the pandemic will be over once we reach 70 percent minimum coverage in vaccination."

Asked by AFP if that figure was still a target or whether more people would need to be vaccinated, Kluge acknowledged that the situation had changed due to new, more transmissible variants, such as Delta.

"I think it brings us to the point that the aim of a vaccination is first and foremost to prevent more serious disease, and that's mortality," he said.

Epidemiologists now suggest that it is unrealistic that herd immunity can be reached solely with the use of vaccines, though they remain crucial to contain the pandemic.