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Coronavirus vaccination: What are we actually waiting for?

11.09.2020

Fast, faster, fastest: Developing an effective SARS-CoV-2 vaccine in record time — is it possible? And will it be the full answer to the pandemic? DW asked an expert a few basic questions about what we can expect.

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.

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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.

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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.

Coronavirus rules: How much physical distancing is enough?
Keep your distance, please!

These are the coronavirus rules as we know them: Keep a distance of 1.5 to 2 meters (5 to 6 feet) from others, observe good hygiene and wear a mask. But this does not do justice to the complex reality of how aerosols spread, researchers from Oxford and London (UK) and Cambridge MA (US) have written in an analysis published in the British Medical Journal in late August.

Coronavirus rules: How much physical distancing is enough?
This much? Or more?

British Prime Minister Boris Johnson has tried to show schoolchildren how it should be done. But what does his gesture mean exactly? Do his fingertips have to be 1.5 meters away from the fingertips of another person? That would be a reasonable interpretation of the regulations. But two arm lengths alone measure 1.5 meters, so distances of 4.5 meters or more could easily result.

Coronavirus rules: How much physical distancing is enough?
Are sheep lengths better?

The Icelandic Association of Sheep Breeders has established its own rules: Two sheep lengths are appropriate to avoid infection. One may wonder if face masks are also supposed to be knitted from real sheep's wool. This young shepherd in Senegal may be trying to find out how long a sheep is by pulling its hind leg. The Icelanders already know — exactly 1 meter.

Coronavirus rules: How much physical distancing is enough?
Natural spacers

Of course, this could also work. The standard length of a dog leash corresponds pretty exactly to the current coronavirus rules. Could it be a coincidence that a six-foot leash is usually prescribed for places where leashes are compulsory?

Coronavirus rules: How much physical distancing is enough?
Where does the 2-meter rule come from?

The authors led by Lydia Bourouiba, an expert in fluid dynamics and disease transmission at MIT, writes that the rule is outdated. Two meters was the distance recommended by the German physician C. Flügge in 1897. Visible droplets that he had caught within this distance were still contagious. A 1948 study showed that 90% of streptococci coughed out in droplets flew no further than 1.7 meters.

Coronavirus rules: How much physical distancing is enough?
Two meters are not enough

The 1948 study was published in the American Medical Journal. It also showed that 10% of streptococci flew much further: up to 2.9 meters. If that were the case, perhaps the people on this lawn on the banks of the Rhine in Dusseldorf would be safe — if every other circle remained free. But wait a minute — we are not dealing with streptococci (bacteria) here, but with viruses.

Coronavirus rules: How much physical distancing is enough?
Viruses spread via aerosols

Viruses are much smaller than bacteria, so they can float around for hours and spread better in the air. This is why the researchers recommend that the distance between people should not be the only safety criterion but that other factors should be considered, too: How well a room is ventilated, whether people are wearing masks, and whether they are silent, speaking softly or singing and shouting.

Coronavirus rules: How much physical distancing is enough?
Do not sing or cough

Numerous studies have also shown that coughing can propel veritable parcels of viruses up to 8 meters through the air. Speaking or singing loudly also spread a lot of aerosols and droplets about the room. If, however, people only speak quietly, as in a library, and sit in the fresh air, safe distances can be smaller again.

Coronavirus rules: How much physical distancing is enough?
How long should I stay in the room?

The duration of a stay in a contaminated room and how many people are in that room are also decisive factors when assessing the risk of infection. The researchers have used those factors to develop a traffic light model. The clear result: In rooms with a high occupancy, you should generally stay only for a short time, make sure they are well aired, wear a mask and speak quietly.

Coronavirus rules: How much physical distancing is enough?
One minute is enough to get infected

Even very brief contact can be enough to transmit SARS-CoV-2. The US Center for Disease Control (CDC) had to tighten its rules on October 21, after a prison guard caught SARS-CoV-2 from prisoners with whom he had only had contact with for a few minutes at a time. Now, "close contact" is defined as being within 2 metres of an infected person for at least 15 minutes cumulatively within 24 hours.

Coronavirus rules: How much physical distancing is enough?
No mask needed here

Here, however, the traffic light of the UK-US research team would show green. Outside, people can be safe for long periods of time even without a mask, provided there are few people around, everything is well ventilated and no one talks much. But even so, will the distance between deck chairs being measured here be enough?

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Julia Vergin