The third Corona winter is just around the corner – and with it not only new waves, but also new variants. Because the virus is far from gone, says Leif Erik Sander. In an interview with ntv.de, the immunologist and vaccine researcher at the Berlin Charité explains what we have to prepare for in the coming months, how well the adapted vaccines protect and when the pandemic will be over.

ntv.de: Professor Sander, after almost three years of coronavirus and billions of vaccinated people, the most pressing question is: when will this pandemic finally be over? Most recently, it was said from several sides that the virus was now endemic. What do you mean?

Leif Erik Sander: The Sars-CoV-2 coronavirus is endemic in the sense that it is now native here and the population often comes into contact with it. Nevertheless, it differs from other endemic viruses because it still changes very rapidly and triggers high waves of infection in quick succession. These are also noticeable socially, since in these waves many people fall ill at the same time, are absent due to illness and, with very high numbers of infections, hospital admissions and serious illnesses also increase. We do not experience this in this way with the old endemic corona viruses. Influenza also usually leads to a single wave of infection per year. So it’s not yet a normal situation like it was before 2020. Whether you call it endemic or pandemic doesn’t really matter to me. One thing is certain: It is not yet a conventional cold virus.

So there will be no end-of-pandemic party?

There probably won’t be a crucial moment from which we can say that from now on the corona virus will no longer play a role. This process is slow. But today we have a completely different situation than a year ago when we had a lot of Covid patients in the intensive care units. Now we have a much more relaxed situation. Individuals have significantly less to worry about. We are on the right path. We have a steadily increasing immunity of the population, which means that infections with the corona virus can be increasingly mitigated. However, this pandemic is not quite over yet.

Concerns about another violent winter wave are currently high. The vaccines adapted to Omicron raise hopes. Will these get us through the cold season well?

There will be more corona infections again this winter. The adapted vaccines are helpful, as initial data show that they can be used to achieve improved neutralization of the currently circulating BA.5 viruses. The hope is of course that with a high booster rate, even with the so-called hybrid immunity after the infection has been overcome, a dampening effect on the coming corona waves can be achieved. But we will not be able to rely on these effects alone in the short term. Unfortunately, it is not possible to completely prevent infections through vaccination. The corona virus is currently mutating very quickly and is trying to dodge the immune response better and better. This can trigger new waves of infection again and possibly present us with certain problems again.

Does the protection against infections with the adapted vaccines wear off just as quickly as with their predecessors?

We don’t even know yet how pronounced the infection protection provided by the adapted vaccines is. There is no data on this yet. But I’m assuming that here, too, the protection will wear off again after a while. If a new variant spreads that evades the antibody response even more, the protection against infection could even drop off again very quickly or be abolished. Protection against serious illness, on the other hand, should be largely retained. It has also previously proven to be very stable.

Could the omicron subline BQ.1.1 be such a variant?

BQ.1.1 is also increasing in Germany and could prevail here in a few weeks. But the question is whether even more immune-volatile variants will come. In my opinion, this could be in store for us in Europe by the end of the year. Because we observe variants, for example from Asia, that are changed at even more points of the spike protein with which the virus infects our cells. Protective antibodies also bind to these sites, and this allows these variants to evade the vaccination protection to a greater extent. That doesn’t mean that a lot of people will get seriously ill again. But the number of infections could increase significantly. This in turn leads to the well-known problems: staff shortages and a higher burden on hospitals and possible complications.

As is well known, young people have a lower risk of developing serious illnesses from Covid. Would you still recommend a second booster, i.e. a fourth vaccination?

There is a very good STIKO recommendation for whom a fourth vaccination is an option. These are primarily people who have an increased risk of a severe course or who have a lot of contact with vulnerable people through their function as medical staff. We see in the case mortality from Covid-19 that it increases significantly in people from around 60 years of age. I would definitely advise these people to get a second booster. Here it is very well proven that it has a benefit. For other groups of people, the benefit is not yet so clear. I don’t see any compelling urgency for a fourth vaccination. However, there are of course also reasons for younger people to protect themselves as optimally as possible. If it has been a long time since the last contact with the antigen, either by vaccination or by infection, the adapted booster is a good option. So I would definitely not advise against it.

Now there are more and more voices questioning the safety of the mRNA vaccines. Some experts claim that there are more side effects than assumed and are calling for the vaccination recommendation, especially for young and healthy people, to be reconsidered. How do you rate that?

Both the national and multinational monitoring systems worldwide as well as many systematic studies confirm a very good safety profile of the approved vaccines across the board. Above all, Israel, but also the USA, provide very good and detailed data that show that there are no new conspicuous security signals. Of course, that doesn’t mean that vaccination damage can’t occur in rare cases. The rare inflammation of the heart muscle or pericardium in young men is described very well and very early on. All vaccination complications must be taken seriously and, above all, documented and treated as best as possible. There are always studies, surveys and statistics that question the safety profile of vaccinations. That’s important and right. But I haven’t seen any study that actually shows a relevant security issue.

So nothing has changed in the risk/benefit analysis?

no Of course, the recommendations are constantly being reconsidered and adjusted. For example, the benefit of the basic immunization in a young healthy person was significantly higher than the benefit of a second booster. And this ratio is also different for children than for a 40-year-old or even an 80-year-old person with previous illnesses. If you have already been vaccinated several times and may have already been infected, the benefit of further vaccinations in non-risk groups decreases.

In view of the new variants, can it happen that the vaccines no longer work at all at some point?

No, it is not to be expected that we will lose our immune protection or turn it completely to zero. Most people are vaccinated, most have also had an infection. With this combination, a very solid and broad immunity is built up. While new variants can reinfect, they definitely can’t attack the lungs and cause severe disease as easily as they could a year or two ago. So I’m optimistic about that. However, I am less optimistic that we will have a permanent calm in the number of infections this winter. The virus is currently changing so much that you can get infected again every few months. But that too will calm down over time.

Corona still seems to be one step ahead of us…

Of course you have the feeling of chasing the virus. Unfortunately, that is indeed the case. At least I didn’t realize that the evolution of Sars-CoV-2 was going so fast. In addition, we humans tend to only react when there is a very acute danger. We’re not particularly forward-thinking. But for some things that doesn’t work. For example, it is currently not possible to develop and approve vaccines so quickly that already cover the next variant and the one after that. Of course you can speed up other processes, but you will always lag behind in a certain way and unfortunately will probably never be able to get ahead of the wave. Nevertheless, my outlook remains optimistic, as we will return to normality in the foreseeable future with increasing immunity.

Mit Leif Erik Sander sprach Hedvig Nyarsik