The fourth wave of corona is just beginning to build up. Behind it - and still far away - the next one could already be brewing if we do not act now, warns the Robert Koch Institute (RKI). Its president, Lothar Wieler, makes the further course of the pandemic dependent on two factors. One of them concerns the fourth wave, the other the fifth.

"The further course of the winter depends strongly on what happens now," Wieler tells dpa. And further: "If the reduction of contacts and vaccination does not succeed intensively, we will also get a fifth wave according to the current modeling." It is therefore necessary to turn these two adjusting screws, the microbiologist and veterinarian made clear. Contact restrictions would take effect in three to five weeks, vaccination in the medium term.

The chairman of the Standing Commission on Vaccination (Stiko), Thomas Mertens, blows the same horn: He does not believe that the incidence of infection can be contained in the short term by increased vaccination. "It must be said that vaccinations at the moment can actually no longer play a role in overcoming the acute situation," he told the Phoenix television station on Friday evening. "We will not succeed in breaking the fourth wave with vaccination."

RKI head Wieler, therefore, calls for "rapid action now to ensure that people's contacts are restricted throughout Germany." The effects of this would be seen after two weeks in the infection figures, he promises. It is important, he says, that federal states that are currently not quite so severely affected also take preventive action. There, he says, there is still a chance to keep the numbers down. "Where the numbers are high, it's actually very late, if not too late," Wieler says.

With an eye on a fifth wave, the RKI president calls for a "massive" increase in vaccination activities. "The vaccine is the way out of the pandemic," Wieler says. "But it is not, therefore, the case that other measures can be completely neglected." That's not easy to communicate, he says. Vaccination communicates a very, very high level of protection. "What may not be fully understood by some people is that there is not 100 percent protection and that protection from infection is not as high as protection from severe illness."

Stiko head Mertens also believes a fifth wave is possible. "It is to be expected that there will also be a fifth wave in the winter of 2022," he told Editorial Network Germany. "How strong this will depend largely on how many people get vaccinated and boostered."