Incidentally, together with our team from CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, MedUni Vienna and AGES, we also describe a recombinant mixed variant that does not appear anywhere else in the databases: a BA.2 virus that has switched its spike protein itself (surface protein with which the virus attaches to human cells, ed.) by that of a BA.1.1 virus. So far, we have detected two such cases.
In order to be able to assign a combination of letters to such a subvariant, a certain minimum number of cases worldwide in the databases is required. And the same applies here: so far there is no evidence that this subvariant would be equipped with epidemiological or clinical changes in properties.
So it’s still not possible to make a final judgment on all these new subvariants?
If there is currently talk of a 20% growth advantage for the subvariants in New York, it might be different again next week because the database is still not that broad and stable. We already know from recombinant subvariants from England that the assessment of their properties depends very much on how many cases have been evaluated and on how good the epidemiological surveillance is for a longer period.
So there is evidence that the subvariants in New York and also the XE variant are showing an increased rate of growth, but this will have to be looked at more closely in the coming weeks as well as how far they are spreading and whether they are gaining a foothold. point of support in other countries. So it seems to me that it’s a little premature for a definitive judgment.
So far, infectivity has increased from variant to variant. Can we assume that this will continue to be the case in the future?
We can assume that new subvariants, which will cause more new infections in the future, will be more infectious. Otherwise, they would not be able to assert themselves. The mechanisms, on the other hand, whether through higher viral titers, an altered pattern of infection in the respiratory tract, or escape from the immune response, may be different.