The places with the highest risk of being infected with the coronavirus SARS-CoV-2 and how students and teaching staff can best protect themselves during the winter – these are the subjects of an interview with occupational health physician Dr Andrea Steiner and infection medicine specialist Prof. Mathias W. Pletz of Jena University Hospital.
For some days now, the health authorities have recorded a strong rise in new cases of the coronavirus SARS-CoV-2 throughout Germany, and especially in the big cities. Does that surprise you?
Pletz: No, on the contrary, it was to be expected. We know that the other types of coronavirus, which have been with us for decades and which cause around a tenth of all common colds, follow a seasonal pattern, with rising numbers of infections in autumn and winter. Therefore, such a pattern was also to be expected for SARS-CoV-2.
However, the fact that the numbers are now rising to such an extent is not only due to the weather; it is also linked to the easing of the contact restrictions that were in place in spring. People have once again become less cautious, as could already be seen during the summer months. And this is shown very clearly when we look at exactly where the case numbers are on the rise – where there are outbreaks. This is not happening in public institutions or on public transport, where most people take care and keep their distance. Instead, it is happening in the private sphere, at parties among friends and within the family, where people feel safe.
What is your current assessment of the resulting danger?
Pletz: At the moment, in spite of the increasing numbers of infections, we do not have a large number of serious cases. Of course, we will have to wait and see how things develop over the coming weeks. But there are definitely possible reasons why we currently have fewer serious cases in relation to the total number of people infected than at the beginning of the year.
What is the reason for that?
Pletz: There are various possible causes. First, over the summer it was mainly younger people who became infected, mostly while travelling, and they are more likely to have mild symptoms. At the other end of the scale, elderly people and those with chronic conditions, who are aware of the risks they face, are especially careful.
Second, effective therapies have now been developed, which can stop people from becoming seriously ill and can reduce the mortality rate.
Third, we know that the level of the viral load plays a decisive role in determining how severely ill a person will become with COVID-19. This means that the basic rules of distance, hygiene and wearing a face mask help, even in the event of an infection. A person who becomes infected, despite wearing a mask or observing social distancing, will receive significantly fewer virus particles and will then usually have a milder illness. Because the virus replicates exponentially, the immune system is able to produce antibodies before the viral load reaches a critical level.
And fourth, it is also being discussed whether SARS-CoV-2 might possibly be mutating and is therefore less dangerous. However, this cannot be confirmed on the basis of the data that are currently available.
The lecture period in the winter semester is approaching. After a summer semester that was conducted virtually completely online, there will once again be lectures at the University of Jena that students and lecturers can attend in person. What must students and teaching staff bear in mind in order to minimise the risk of being infected with the coronavirus?
Steiner: First and foremost are the essential rules: maintaining a distance from other people; following the hygiene rules, such as regular hand-washing, coughing and sneezing into the crook of the elbow; and wearing a face mask. Three things should also be avoided: enclosed spaces, large groups of people and conversations in close proximity to other people. These recommendations can be found, for example, on the FAQ pages of the University’s website. We should update our information regularly and observe these rules as a matter of course. In this way, everyone can help to avoid infections and to protect those who are particularly at risk, such as the elderly.
There are further rules for courses attended in person. For example, all participants have to register, so that contacts can be traced. You should of course only attend a lecture or seminar if you feel well. Every participant has to make a declaration to that effect before attending any lecture or other event.
Since the start of the school year, teachers in schools, but also nursery staff, have been entitled to free, regular virus tests. Are there plans to give teaching staff at the University this opportunity, too?
Steiner: No, there are no plans for this as yet.
Why not? Some universities in other countries test students and lecturers.
Steiner: Because the risk of infection for university lecturers is significantly lower than for an early years teacher at a nursery. Our hygiene rules constitute an effective approach for minimising the risk of infection at the University. At a nursery or a primary school, it isn’t possible to adhere to social distancing rules to the same extent, for example.
Pletz: It must be added that it’s also a cost-benefit issue. At the moment, the costs of comprehensive, regular testing cannot be justified. But the further development of diagnostics will be sure to bring reductions in the prices of coronavirus tests. If, in addition, the situation in Germany and Thuringia were to change substantially, we might come to a different assessment at a later date.
In what circumstances should I, as a member of the teaching staff, nevertheless have myself tested?
Pletz: It isn’t easy to make a general statement about that, because there are no absolutely clear and unambiguous symptoms for a SARS-CoV-2 infection. However, if there have been confirmed cases of COVID-19 in the vicinity and if you develop symptoms such as a cough, fever and a loss of your sense of smell and taste, or if you actually suffer from shortness of breath, then it would definitely be advisable to have a test.
How many coronavirus tests are currently being carried out at Jena University Hospital and who is being tested?
Steiner: An average of 500 tests per day are currently being carried out in the University Hospital lab. These involve not only samples from Jena University Hospital, but also from the hospital in Eisenberg, as well as the special “fever surgeries” of Jena’s health authority. At the Occupational Health Service of the University and the University Hospital, we are testing between 20 and 30 workers a day, and the trend is upwards. This includes samples from people who have returned from journeys and contacts of people who have tested COVID-positive, as well as routine screenings of hospital staff who treat COVID patients.
What does a negative test result reveal? How much certainty does a coronavirus test actually provide?
Pletz: The most commonly used test method is the PCR test (see information below), which is, however, just a snapshot and only provides 70% to 90% certainty of a correct result. Therefore, a negative test does not mean in every case that a person does not have a SARS-CoV-2 infection. The situation is similar for the antibody tests (see information below). We saw this in our Neustadt study: in half of the patients who were shown to be infected with SARS-CoV-2, that is to say that they had had a positive PCR test, we were unable to detect any antibodies six weeks later. This means that the antibody status is also only a snapshot and doesn’t really allow us to state whether or not a person has long-term protection from an infection. Conversely, testing negative for antibodies does not exclude a previous infection.
The season of colds and flu is just beginning. How can cold and flu symptoms be distinguished from those of a coronavirus infection?
Pletz: Just on the basis of the symptoms, not at all. This is because common colds, as well as flu and SARS-CoV-2 infections, can progress in very different ways: from extremely serious cases to a complete lack of symptoms. What we can say about SARS-CoV-2 is that it is often accompanied by a loss of smell and taste, although only in around one in two patients. This is therefore not a reliable distinguishing feature.
Steiner: By contrast, the classic symptoms such as a cough, a runny nose and fatigue occur in all these diseases, so that a layperson cannot distinguish the disease on the basis of the symptoms. However, we can all protect ourselves against influenza! People should in any case have the flu vaccination.
Does a flu jab therefore also offer protection against cold viruses or the coronavirus?
Pletz: Not directly. However, there are published observational studies that suggest some indirect protection and show that patients who have been vaccinated against flu have a lower mortality risk in the event of a COVID-19 infection. This is due to a non-specific vaccine effect. The vaccine stimulates the immune system as a whole and if a person is infected during this phase, the illness is usually milder, because the immune defence is already active.
Are there groups of people for whom such a vaccination is not suitable?
Steiner: No, a flu vaccination is in principle suitable for everyone. It involves what is called an inactivated vaccine, which does not contain viruses, but only virus particles, and it is therefore very safe. The only drawback of such a vaccine, which can occur in immunocompromised patients, for example, is that the immune response that is provoked is not strong enough. Even so, it makes sense to be vaccinated.
There is also a live vaccine specially for children, which can be administered as a nasal spray. This has been developed to make the annual flu jab more pleasant for children and their parents. As the name suggests, this vaccine contains active influenza viruses. In otherwise healthy children, however, these are only active in the nose and cannot spread through the body. This form of vaccine is not permitted for immunosuppressed patients. But in principle, everyone should consider getting a flu jab.
Pletz: To achieve this, I would like to see the Standing Committee on Vaccination recommend that children should generally be vaccinated against flu. This is already the case in Saxony, which has its own committee on vaccination. In contrast to SARS-CoV-2, there are clear data for flu showing that children shed significantly more virus than adults and also continue to be contagious for longer, so they have a much greater influence on the occurrence of infection. Results of studies show clearly that when children are vaccinated against flu, the mortality rate of those aged over 65 declines.
Why has there not been such a recommendation to date?
Pletz: Vaccination is recommended, but only for high-risk groups – the elderly and people with existing medical conditions. This is because in Germany we only have around 25 million doses of vaccine for this season. And as long flu vaccine remains in short supply, high-risk patients must of course have priority.
PCR (polymerase chain reaction) tests detect the specific genetic material of viruses. For this test, swabs are taken from the mouth, nose and throat, and analysed in the lab. The test can also determine the virus concentration, or viral load. If the test result is positive, it means that when the sample was taken, the patient was infected with the virus. The PCR test therefore only provides a snapshot.
Antibody tests do not detect the pathogen itself, but record the reaction of the immune system to contact with the virus. If the body is infected with the virus, the immune system produces antibodies. However, this only occurs after a few days. Therefore, the antibody test mainly serves as evidence of a past infection. Antibody tests cannot show whether the person tested is still infectious, how long ago the infection occurred or whether the person still has sufficient protection against a new infection. These tests are therefore more suitable for finding out how many people in the population have already experienced the infection.