In the debate about possible relaxations of Corona measures in Germany, virologist Christian Drosten believes the time has not yet come to sound the all-clear. "There is one thing that has not changed for now. That is the vaccination gap in Germany. Since we do not come so properly forward," said the scientist from the Berlin Charité on Tuesday in the podcast "Coronavirus Update" at NDR-Info. Recently, the vaccination rate has even dropped again. For example, in Denmark, the Corona restrictions now largely fell in view of the high vaccination rate - but in Germany, the situation is not comparable, he said. "That's why we can't give the all-clear for Germany," Drosten said.

The virologist suggested that Omicron's new BA.2 variant could have an even higher transmissibility than the BA.1 subtype currently prevalent in Germany, adding that based on new data from Denmark, he suspects BA.2 may have a so-called fitness advantage and thus increased transmissibility.

Drosten explained the assumed difference between the two subtypes with the metaphor of two cars, saying with regard to BA.2: "The engine, it already has a few horsepower more." With BA.1, on the other hand, he said, he believes the variant may be evading the body's immune response, which is why it spreads so quickly.

The Danish study data published in preprint - that is, without peer review - indicated that the risk of infection was significantly higher with BA.2 than with BA.1. According to the data, the risk of passing on the virus is also greatly increased in infected unvaccinated individuals, but reduced in vaccinated contacts.

The proportion of BA.2 in Germany "remains very low" at 2.3 percent in the second week of the year, according to the latest weekly report from the Robert Koch Institute (RKI). The week before, it had been 1.4 percent. Regarding the subtype, the RKI writes, "Internationally, BA.2 is observed to be spreading more than BA.1." That affects Denmark and the United Kingdom, for example, it said.

Drosten said in the podcast that the proportion of BA.2 would probably also increase in Germany - but possibly more slowly than in other countries because of the infection protection measures in place. More precise predictions cannot yet be made, however, because of the limited data available.

He sees the coming Easter vacations as a time threshold and a "planning horizon" for easing the Corona situation, the virologist said. "We have very clear findings in Germany that the transmission networks are being fed by school operations at the moment. The Easter vacations will then put the kibosh on that at the latest," he said. The warmer temperatures are also likely to have a lowering effect on incidences. It remains to be seen whether BA.2 will have "completely taken over the field" by then.

Drosten said the "ideal immunization" is complete vaccination protection through three vaccination doses, on the basis of which one is then infected with the virus once or even more frequently and thereby develops such strong immunity "without having to accept severe courses." Whoever has gone through this, "is then at some point really resilient for years, immune and will not be reinfected again," said Drosten.

Referring to the many unvaccinated people in Germany, he repeated his warning against allowing contagion to take hold. He strongly criticized the mindset that an infection with one of the omicron variants could substitute for vaccination, pointing to the high probability of repeated infections. Therefore, the bill "of Omicron infection as vaccination through the back door" simply does not add up.

In the debate over Corona relaxations, German Justice Minister Marco Buschmann (FDP) holds out the prospect of a far-reaching rollback of Corona measures in March. "I hope that many protective measures can be withdrawn in March," Buschmann told the newspaper Rheinische Post. The prerequisite, he said, is that the infection incidence develops as predicted by the Robert Koch Institute "and from mid-February, the case numbers fall again. And it presupposes that we don't have to deal with new variants of the virus in the short term that completely change the situation again."

Image by Gerd Altmann