“We were lucky that omikron turned out to be so mild,” says Ugur Sahin. The co-founder of the German biotech company BioNTech will launch a modified vaccine on the market in September.
At the beginning of 2022, you developed a vaccine that would protect against the omikron variant of the coronavirus, but that special booster is still not approved. Could you have saved yourself the trouble?
Ugur Sahin: It still makes sense to make adapted vaccines. The spike protein – the structure the vaccine targets – of the omikron variant is significantly different from that of the original type. Our data show that a booster with a modified vaccine produces a lot more antibodies against omikron. The immune system is therefore better able to fight off the variant. At the same time, we must not forget that omikron is already partly a so-called escape variant (a variant of the coronavirus that can escape the protection built up by a vaccine or a previous infection, ed.). We could be dealing with a variant that does not react at all to the antibodies of the original vaccine. We must guard against that.
How can a booster against omikron help?
Sahin: Omikron has several mutations in the spike protein, so that only some parts are still recognized by the antibodies of someone who has been vaccinated with the vaccine against the original virus. The virus continues to mutate at lightning speed. It is difficult to predict when the variant will no longer be recognized by the original vaccine. That is why it is important to show the immune system as many of these mutations as possible so that it learns to recognize future variants.
If the benefits are so obvious, why were the doses sitting in the freezer for months waiting for approval?
Sahin: This is the first time a modified vaccine has been approved. The authorities wanted to see a lot of extra data – for example whether a modified vaccine should be based on omikron only, or both omikron and the original variant. Such a clinical study takes four to five months.
We want to create a vaccine that targets the non-mutating parts of the virus.
In Germany, the omikron booster would be approved this week. Can you deliver doses immediately?
Sahin: Yes. We made two different versions. One is based on the BA subtype. 1 from omikron. For this we have submitted all necessary data to the European Medicines Agency. The second vaccine is based on the BA. 5 subtype, which is currently dominant in the EU. We are submitting the final documents for this. It can also move quickly, depending on how quickly it is assessed.
So there will be two different omikron boosters available at about the same time. Isn’t that confusing?
Sahin: There is no big difference between the two. According to our research, both manage to produce more antibodies than the original vaccine. At the same time, we have clear indications that the BA. 5 vaccine is more effective against the BA. 5 subtype.
The US only wants the BA. 5 booster. Do you have a personal preference?
Sahin: I advocate staying as close to the dominant tribe as possible.
Will more subtypes of omikron emerge, or is there a new, potentially dominant variant lurking?
Sahin: 99.8 percent of cases are now caused by omikron. The variant will therefore not be easy to supplant. But an unsolved problem is that highly mutated variants also appear out of nowhere, as it were. We cannot predict them because the virus is reinventing itself.
Should we prepare for an annual booster shot against the dominant variant? Or will there soon be a new generation of vaccines that will protect us for a longer period of time against a broader spectrum of variants?
Sahin: We are testing different approaches for a new generation of vaccines. I’m excited about an approach that targets another defense mechanism of the immune system: the T cells. There are studies that show that people have fought off the virus without measurable antibodies. The T cells only managed to knock out the virus. We’re investigating that. The aim is to create a universal T-cell vaccine that targets the non-mutant parts of the virus, and will protect us from both severe and mild disease, regardless of which variants are circulating in the future.
Will the approval processes also become shorter?
Sahin: This is important. Not only do we need improved vaccines, we also need to be able to respond more quickly.
Would the process then be comparable to that of the flu vaccine, where an adaptation to the current vaccine does not have to be accompanied by a clinical trial and does not have to be re-approved every time?
Sahin: I would be surprised if we didn’t find an internationally recognized solution at the latest next year, such as with the flu vaccine. That has to be. We were lucky that omikron is not a real escape variant, that a booster of the current vaccine already offered some protection and that omikron is less pathogenic than delta. We cannot count on the next variant to be so mild.