Prof. Hartmut Hengel is the medical director of the Institute of Virology at the Freiburg University Medical Center and the deputy chairman of the Scientific Advisory Board of the Paul-Ehrlich-Institut

Prof. Hartmut Hengel is the medical director of the Institute of Virology at the Freiburg University Medical Center and the deputy chairman of the Scientific Advisory Board of the Paul-Ehrlich-Institut

Progress thanks to the chemical industry

Readingtime 4 minutes

The Freiburg-based virologist Professor Hartmut Hengel talks about the prospects for the rapid development of a vaccine against the coronavirus, the advantages of RNA technology, and the role of the chemical industry in new vaccination procedures


Professor Hengel, in the discussion about a coronavirus vaccine, more and more skeptics are speaking up. They’re saying that vaccinations have caused cancer and other diseases, overburdened the immune system, etc. Is there any truth to these assertions?

All of them can be scientifically refuted. Basically, even higher safety requirements apply to vaccines than to medications, because vaccines are administered to healthy people. Modern research is making huge efforts to offer vaccines that have a minimum of side effects. However, in the past some vaccines have in fact caused undesired effects. That’s why comprehensive safety testing is so important.

That takes time, and during the battle against the coronavirus pandemic time is in especially short supply. What shortcuts could be taken so that we can administer a proven vaccine to end the pandemic as soon as possible?

Each society has to answer for itself the question of how to deal with this process at the ethical and political levels. In my opinion, we have to proceed carefully and conduct stringent testing. I think it would be not only risky but also unethical to administer a vaccine that has not been properly tested to the general population. You first have to investigate how long the protection will last and the safety aspects over time. Especially in cases where side effects occur only very rarely, these side effects might be seen only years later.

Many fears are related to gene-based vaccines, which are currently going through several approval processes. There are fears that they could alter the genetic material of the vaccinated individuals. Are these fears justified?

The vaccines that are currently being discussed in connection with SARS-CoV-2—the novel coronavirus— are primarily vaccines whose mechanism of action is based on ribonucleic acid, or RNA. The RNA converts genetic information into proteins, and—according to everything we know—it is not integrated into the genetic material of human beings. I have no fears of that.

One of the reasons why RNA-based vaccines look so attractive is that they can be produced in large quantities in a very short time. How soon will a vaccine be available?

In the case of a few vaccine candidates, we’re hoping that one or more of them may still be approved in 2020. However, we can only arrive at a comprehensive safety assessment in the course of a vaccine’s actual use

In the case of other viral diseases such as measles, it’s known that 95 percent of the population must be immune in order for unvaccinated individuals to also be protected. Is that also true of the coronavirus?

We don’t know. One difference between the measles virus and SARS-CoV-2 is that there are people who were infected with the coronavirus but did not produce any antibodies. It’s even possible that herd immunity against SARS-CoV-2 will fail to materialize because coronaviruses are programmed for reinfection. If we succeed in developing vaccines that lack the functions of the virus that are responsible for “immune evasion,” a vaccination could even protect us more effectively than a previous infection.

What role is the chemical industry playing in the development of potent vaccines?

A very important role. For example, take the lipid nanoparticles that are used in mRNA vaccines. Transfection reagents of this kind are a key determinant of the effectiveness of the vaccines, because they enable the mRNA to be transferred into the cells. They determine which cells the vaccine can penetrate, as well as how effective and stable it will be. If this method is successful against the SARS-CoV-2 virus, it would be an entry point into a new class of vaccines, and maybe even into completely new principles of vaccination.

Are you saying that this technology could solve problems for which there is no solution at present?

Absolutely! I can even imagine that in the future we will produce cocktails of messenger RNAs and thus combine multiple vaccinations. That would make it possible to generate much higher levels of immunity with far fewer individual vaccinations. It would be a big step forward.

Will there one day be vaccinations against all diseases, ranging from cancer to Parkinson’s disease and all the way to diabetes?

It would be naive to believe that through vaccinations we can eliminate all diseases. However, I expect that in the future we will be able to block more infectious diseases by means of vaccinations. But we have to be patient. That’s why I’m not happy at all about the current talk about a “race” to develop a vaccine against SARS-CoV-2. The winner is not necessarily the one who starts out fastest. This is a marathon, not a sprint.

Photo: Jürgen Brandel




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