Status: 10/27/2022 2:39 p.m
The new corona variant BQ.1.1 is slowly spreading in Germany. In an interview with tagesschau.de the bioinformatician Neher explains what this can mean for the winter and how virus variants arise in the first place.
tageschau.de: How common is the new corona variant and what distinguishes it?
Richard Neher: The so-called BQ.1.1 variant has changed at a number of positions in the genome and seems to be gaining ground in parts of Europe. It descends from the variants that were already circulating here in the summer. However, in addition to the mutations that these summer variants had, there are a number of other mutations at positions that allow BQ.1.1 to at least partially circumvent existing human immune responses.
tageschau.de: So does that mean that people who have been vaccinated three times and who may have had an additional infection can still get infected?
closer: The virus mutates at the sites where antibodies bind to the spike protein. And if the virus changes in these places, then these antibodies, which we have formed, for example, through vaccinations or surviving infections, no longer bind as well. The viruses are therefore no longer recognized so well and can then lead to an infection, although the antibodies are basically there.
Coronavirus variants in autumn: Anja Martini in conversation with Richard Neher, bioinformatician, University of Basel
10/27/2022 1:11 p.m
tageschau.de: What would that mean for the next few weeks and maybe even for the winter?
closer: This variant again has a larger part of the population available to infect. And by having this larger number of potential hosts, it has a transmission advantage, is spreading faster, and could lead to another wave sometime in November.
In France, for example, we see that this variant is already very common and is doubling in frequency every one to two weeks. And from that rate of increase, you can estimate when the wave will come. Estimating how high it will be in the end, on the other hand, is a lot more difficult.
tageschau.de: Are there already figures for Germany?
closer: Because we sequence these viruses on a large scale, we have a relatively good overview of how many viruses of each variant are out in each calendar week. And there we have been seeing for a few weeks now that BQ.1.1 is gradually increasing and also roughly doubling in frequency every one to two weeks.
tageschau.de: You are a specialist in virus evolution. What does it mean exactly when a virus mutates? And how do they detect these tiny changes?
closer: We now have sequencing technologies that can be used to decode the sequence of the bases very quickly. That means we have decoded thousands to hundreds of thousands of these virus genomes in Germany alone, millions all over the world. And you can then compare these sequences and see at which positions in the genome there have been changes.
tageschau.de: Many people probably feel that new mutations are constantly emerging. Is the coronavirus a virus that is particularly prone to mutating, or is that normal compared to other pathogens?
closer: The virus is certainly changing very quickly. But you have to distinguish between two things: On the one hand, the mutation rate, i.e. the rate of programming errors in the genome, is not that high for corona viruses. But the virus is under a lot of pressure to change, and that leads to the rapid accumulation of these mutations, which are right up in the spike protein, where the antibodies recognize the virus. So what we’re seeing is actually an extremely rapid evolution, a rapid adaptation, a selective change in the virus to evade the immune response.
tageschau.de: Would we then actually have to adapt a new vaccine every few months?
closer: With the flu, the vaccine is already updated every year and we typically start a vaccination campaign in autumn and protect risk groups with a new, adapted vaccination. With Corona we are in a bit of a similar situation, except that this virus is changing a lot faster and we don’t just have one wave per year, but several.
tageschau.de: Is it possible that the virus changes so much that it can completely evade all vaccinations?
closer: We have not observed this so far and we do not expect anything like that either. Almost everyone now has some form of immunity, whether it’s through vaccination or through recovering from an infection. And this immunity doesn’t go away either. This means that we do not expect the severe courses that existed at the beginning, when there was no immunity at all in the population, to return.