SARS-CoV-2 vaccination: What are we waiting for?

More than 170 vaccine candidates against SARS-CoV-2 are in the running. Seven of them are in the third and final phase of clinical trials. Processes that normally take years are currently underway at record speed. It is a matter of life (and death), money and power.

That is why vaccine development is also a political issue. US President Donald Trump suspects that the US Food and Drug Administration (FDA) is deliberately slowing down work on an effective vaccine because it wants to prevent him from taking credit for successfully fighting a pandemic before the end of his term of office.

Which brings us back to science: What kind of credit are we talking about here? Will a vaccine really be the panacea it is often made out to be? We put those questions to the immunologist Thomas Kamradt.

DW: When a vaccine is found, everything will be fine — at least, that seems to be many people's expectation. Is this expectation justified?

Thomas Kamradt: Personally, I would be satisfied if there were simply a safe vaccine that perhaps has to be refreshed every two years but that has a massive effect on how seriously the disease progresses.

Maybe the vaccination would not prevent you from getting the sniffles or other mild symptoms. But the minimum requirements would be that it prevents respiratory insufficiency and severe organ damage. So if you ask me what we are waiting for, it is this. If such a vaccine did nothing more than change a life-threatening disease into a mild disease, I would consider it a success. Anything beyond that would be a very big success.

'A Stone Age method'

Recently, there was a report of one new infection where a young man from Hong Kong tested positive for the virus for the second time. Until then, people had hoped that whoever had been through the infection once would be immune. Did the idea of "natural herd immunity" also die with this report?

Quite apart from this report: If you look at the rates of infection and mortality that would be needed to achieve herd immunity, it is a Stone Age method. And it would take for ever to reach such immunity.

What is more, we now also have to assume that immunity does not last for life. So I hope that nobody is looking to natural herd immunity as a solution anymore. Herd immunity as such can be achieved with vaccinations.

There are several strains of the novel coronavirus with which one can be infected again and again. What does this mean for the development of an effective vaccine?

The changes in the viruses are primarily of epidemiological interest because they allow infection clusters to be tracked. So far, there is no evidence that the differences between the various SARS-CoV-2 strains have any great relevance for how effective a vaccine would be. This is different with the flu.

New techniques

Let's talk about vaccine development, which is happening at an incredible speed. Some scientists warn against putting a potentially ineffective and unsafe vaccine on the market just to be as fast as possible. Does the speed of vaccine development also worry you as a scientist?

Not so far. So far, I am just excited about it! It usually takes well over 10 years for a vaccine to become so widely available that everyone can be vaccinated. The previous record is held by the Ebola vaccine, which took about five years to gain approval. And here everything is happening much faster.

There are several reasons for this. First, it was known from the viruses that cause SARS and MERS that the new coronavirus' spike protein is a good target structure for an immune response. This means that researchers did not have to start from scratch with a completely new virus.

There are also completely new techniques. Until not so long ago,  developing a vaccine meant sending viruses all over the world to be cultivated in cell cultures and so on. But here, Chinese researchers put the sequence of the virus on the internet back in January. You could compare it with SARS and MERS viruses; everything went incredibly fast. So the first clinical phase 1 study could already begin in March; that was the mRNA vaccine from Moderna.

The speed of the whole process has also been increased because steps that normally take place one after the other are happening parallel to each other. For example, production facilities are already being created for vaccines that may never exist.

What must not happen at any price, however, is that safety tests are carried out less stringently than usual. As bad as the whole thing is, 80% of those who develop symptoms at all end up with only mild ones. This means that if I vaccinate against a disease like this one, I have to be very sure that I do not cause any harm. After all, I will be administering the vaccination to healthy people.

But you do not see any acute danger as far as the safety tests are concerned?

No, I do not see any indications for concern.

No risk despite the speed

If a vaccine becomes available, the question will arise about who will be vaccinated and, indeed, about who wants to be vaccinated at all. According to an analysis by the Hamburg Center for Health Economics, the willingness of the EU population to be vaccinated against the novel coronavirus is declining. One of the biggest concerns for people is possible side effects. Do you understand this concern?

Communication is very important here. Even experts are amazed at what can be parallelized and sped up as a result. That costs money, but it is not a risk. But, of course, it must still be clear that safety checks cannot be carried out faster and less thoroughly than usual.

We are facing another illness wave: a flu wave. In your opinion, it is particularly important to be vaccinated against the flu this year? Why is that?

First, for personal protection, because we don't know yet whether the immune system is weakened by flu so that it becomes more susceptible to COVID-19.

And secondly, so that not too much strain is placed on the health care system. Influenza also has a certain mortality rate. Symptoms can be similar, so that emergency rooms cannot immediately distinguish between COVID-19 and influenza.

If there are fewer influenza patients in the health care system because more people are vaccinated, there is more space to care for the really sick.

Let us assume that there is a SARS-CoV-2 vaccine. Who should receive the first doses?

Ideally, the vaccine should be effective in elderly people. They have the more severe cases of the disease. The influenza vaccine, for example, is less effective in older people than in younger people, but this can be compensated for by the dosage. That is something clinical tests will have to show.

Then the vaccine should primarily be given to old people and those with preexisting conditions. And also to those who are particularly exposed and to those who have a particularly high risk of spreading the virus.

A young, healthy person living in a hut in the forest is perhaps be the last person who needs to be vaccinated.

Thomas Kamradt is director of the Institute of Immunology at the University Hospital Jena and president of the German Society for Immunology.

The interview was conducted by Julia Vergin.