According to experts, the subline XBB.1.5 of the Corona variant Omikron could also spread in Europe and Germany in the coming weeks and months. "One can say with some prognostic certainty that the variant will also become the dominant variant for us," said the Bremen epidemiologist Hajo Zeeb. But there is no cause for great concern. "We're seeing a little more cases in the US, but there's not a gigantic wave going on there."
XBB.1.5 has rapidly increased in frequency in the northeastern United States and has dominated the infection process there since mid-December, said Richard Neher, head of the research group Evolution of Viruses and Bacteria at the Biozentrum of the University of Basel. Outside of the northeastern United States, the variant is even less common, but the proportion is increasing.
"The basic variant has been known since October," said Zeeb, who heads the Leibniz Institute for Prevention Research. "It was seen for the first time that the combination of subvariants had occurred." The special feature of XBB.1.5 is the even higher infectivity. "That was already developed at Omikron, XBB.1.5 now tops it again."
Easier to transfer than other variants
Corona specialist Maria van Kerkhove from the World Health Organization (WHO) said on Wednesday in Geneva that the subline was more easily transferrable than any of the previously known variants. The EU health authority ECDC announced on Thursday that XBB.1.5 is believed to have a "major growth advantage" over the previously circulating lines in North America and Europe. However, this assumption is still associated with considerable uncertainties.
Federal Health Minister Karl Lauterbach (SPD) has already expressed concern. On Thursday he tweeted: "Hopefully we can get through the winter before such a variant can spread to us."
According to Neher, there is little information about the severity of diseases with the new subline. Cases and hospitalizations have increased across the US, not just in regions where XBB.1.5 is prevalent, the expert said. This is at least a first indication that the severity of XBB.1.5 infections does not differ significantly from that of other variants currently circulating.
Evidence of XBB.1.5 in Germany is still low
And what does the subline mean for Germany? "XBB.1.5 is encountering a receding immunity from people who were vaccinated or infected a long time ago," Zeeb explained. "First in the USA and then also here in Germany." However, the number of proofs of XBB.1.5 in Germany is currently still very low. "You don't have to think about new measures yet."
According to the Robert Koch Institute, the subline was detected for the first time in a random sample in Germany at the end of November. According to the ECDC, it could have an increasing impact on the number of corona cases in Europe, but not within the next month as it is currently only occurring on a small scale. The frequency of XBB.1.5 has been doubling about every week, Neher said. If this trend continues, a share of three to six percent can be expected in the first half of January.
It is important to keep a close eye on developments, said Zeeb. The ongoing sequencing of samples is very important and must be maintained at a high level. To do this, you have to work together across Europe. "A good proportion of cases from all countries should be sequenced. This is important in order to identify really relevant changes as early as possible."