The pandemic as we have known it for almost three years now might soon come to an end. Andreas Bergthaler from the Medical University of Vienna and the CeMM – Research Center for Molecular Medicine of the Austrian Academy of Sciences (ÖAW) assumes this. However, the immunologist does not want to rule out the possibility that a new virus variant will come along.
In the interview, he explains to what extent the omicron variant heralded a paradigm shift, why Long Covid will keep us busy for a long time and what we can learn from this pandemic for future pandemics.
OMIKRON ALSO GAMECHANGER?
Mr. Bergthaler, in an interview with the German weekly newspaper “Die Zeit”, the Berlin virologist Christian Drosten said that the situation for the virus was precarious and that it was in an evolutionary dead end. Do you agree?
Andreas Bergthaler: The virus has surprised us more than once, so I’m cautious regarding making forecasts for the future. However, if we review the mutation process, then the omicron variant, which spread from December 2021, brought regarding a paradigm shift: following new variants such as alpha, beta or delta, we were left with omicron – with all its subvariants.
The virus has surprised us more than once.
Did Omicron’s many ramifications cause the virus to get bogged down?
Bergthaler: All the subvariants have in common that they have accumulated additional mutations, including in the receptor binding site of the spike protein. When the same mutation occurs multiple times independently, it is called convergent evolution. This in turn is strong evidence that the virus is exposed to relatively high immune pressure. Now the virus is trying to escape this immune pressure by mutations at the sites where the antibodies attach.
It may be that we will continue to move in this universe of omicron subvariants. Or a completely new variant will appear once more, which I don’t want to rule out.
Omicron is not much milder than Delta. But: Around 97 percent of the population had immunological contact with virus antigen.
Omicron is seen by the public as a milder variant. Right?
Bergthaler: Omicron is not inherently milder. Data from England showed that Omicron is only slightly milder than the Delta variant, which led to significantly more severe courses than the original Wuhan variant. But: According to calculations, 97 percent of the population has now had immunological contact with virus antigens, either because people are vaccinated, infected or both. This led to broad immunity through antibodies and T cells. Unfortunately, this immunity does not prevent us from becoming infected, but it contributes to the fact that severe cases only rarely occur in healthy people.
HIGH RISK VULNERABLE INDIVIDUALS
So the risk remains for vulnerable people?
Bergthaler: A central aspect seems to me that the pandemic is not over per se, especially not for vulnerable people. From an ethical point of view, we should pay attention to how we can better support people who are at risk so that they can participate in society. This includes the availability of current vaccines and medicines, wearing masks in solidarity at indoor events or an improved indoor climate with cleaner air. All in all, it is not at all easy to precisely define the group of vulnerable people.
We should pay attention to how we can better support people who are at risk.
Even with Long Covid, a lot is still undefined.
Bergthaler: Yes, Long Covid remains the elephant in the room. The level of knowledge on this is still insufficient and it is difficult to pinpoint the molecular causes and the range of chronic consequences. Some calculations assume that up to ten percent of all those infected have longer-lasting symptoms and that these may even worsen if they are infected once more.
SEASONAL EFFECTS, LESS TESTING
How do you assess the current epidemiological situation?
Bergthaler: The seasonal effects mean that the number of infections will increase once more. In addition, we now have a much less precise set of tools to collect individual infection numbers – there is far less testing. Increasingly, attempts are being made to manage the viral load in the wastewater. Overall, I expect that new virus subvariants will always escape our antibody response a little better and thus drive new waves of infection.
Endemic does not automatically mean that everything is fine.
Do you still see the first signs of the transition from pandemic to endemic?
Bergthaler: This is a matter of definition. Pandemics are usually understood to mean supra-regional events involving infectious agents that affect all regions of the world. Endemic, on the other hand, means that only a certain area is affected. An example of this would be malaria, an infectious disease that kills more than half a million people every year. So endemic does not automatically mean that everything is fine.
Crucially, we are no longer subject to short-term waves of potentially systemically critical proportions, as we have been for the past two and a half years. If this positive trend continues, I assume that the pandemic as we have known it is over. It then remains more of a formal matter when the WHO downgrades the pandemic to an endemic or epidemic.
NO COUNTRY WAS WELL PREPARED FOR A PANDEMIC
What can we learn from this pandemic for future pandemics?
Bergthaler: Worldwide, we have seen that no country was really well prepared for this, even if pandemic plans were in the drawers everywhere. What worked extremely well internationally was the rapid development of vaccines. Vaccination built broad immunity in a population that had never encountered this new pathogen, saving severe cases and countless lives.
What worked extremely well internationally was the rapid development of vaccines.
And in Austria?
Bergthaler: Unfortunately, some things went wrong in the controversies and polarizations that followed. If anything might have been avoided in Austria, it would have been the unspeakable discussion regarding compulsory vaccination. This was very politicized from start to finish and unfortunately smashed more dishes than it brought.
Critical retrospective analyzes would be necessary. This requires the appropriate data, which is then scientifically combined and analyzed. There is still a lot of room for improvement, although some progress has been made in the last year. It is to be hoped that we will learn as many lessons as possible in order to be better prepared for future crises of a similar magnitude.
