In a press conference, Hans Kluge pointed out that variants of the SARS-CoV-2 coronavirus diminish the prospect of achieving mass immunity and that the disease is more likely to become endemic without being eradicated.

It is necessary to "anticipate to adapt vaccination strategies", defended Hans Kluge, who in May had declared that "the pandemic will be stopped once vaccination coverage of 70 percent of the world's population is reached".

Asked if this percentage is still valid, the European director admitted that the most contagious variants that emerged and became dominant in several countries - such as Delta, predominant in Portugal - changed the situation.

"I believe that the essential aim of vaccination will be, first and foremost, to prevent severe forms of the disease and mortality," he said, adding that "if it is assumed that the virus will continue to mutate and remain among humans, such as influenza, must anticipate how to progressively adapt the vaccination strategy to endemic transmission and arrive at essential knowledge about the impact of supplementary doses" of vaccines

A high level of vaccination remains essential "to reduce the pressure on health systems that desperately need to treat diseases other than covid-19," he noted.