Moving away from corona incidence: “There is no such thing as zero risk”

The seven-day incidence should no longer play the decisive role, the first federal states are putting more pressure on unvaccinated people. The Munich virologist Ulrike Protzer explains how effective these measures are.

tagesschau.de: The federal government is planning to move away from the number 50 as a seven-day incidence in the pandemic. The right time?

Ulrike Protzer: I think that is very sensible. We’ve been advising this for a while. The incidence says nothing about how many really relevant, more dangerous infections we have. The significance for the burden of disease is completely different here: depending on whether young or old people are affected, or vaccinated or non-vaccinated. A separate, at least as important measurement factor is required for the burden of disease.

tagesschau.de: What are you suggesting?

Swanker: In my opinion, the admission of Covid-19 patients to the hospitals is a good parameter – i.e. the so-called hospitalization rate, which of course has to be set in relation to the number of inhabitants. You can divide it up regionally and determine it on a daily basis. This shows how high the burden on hospitals is – and what development is expected. The expected occupancy of the intensive care units can also be derived from this.

“Those who do not vaccinate are consciously taking a risk”

tagesschau.de: Nevertheless there is criticism. The SPD health expert Karl Lauterbach speaks of a “cynical decision” now that the incidences are increasing significantly. In addition, this indicator is lagging behind the actual infection process.

Swanker: You just have to keep an eye on both – the incidence values ​​and the hospitalization rate. The incidence of infection is relevant to have an idea of ​​what is happening to us. The hospitalization rate helps us control. Because we will not get the infections completely to “zero”.

And everyone now has the opportunity to protect themselves with a vaccination, sometimes with the exception of children under the age of twelve. Anyone who does not do this is deliberately taking the risk of infection. At a certain point, it is important to consider how much society invests in protecting those who do not want to protect themselves. If you have to shut down the economy or close schools because of this group and the high incidence it causes, then I find it difficult. Because it has significant consequences for the rest of society.

tagesschau.de: Isn’t politics taking this step of moving away from incidence at the expense of children who cannot and should not be vaccinated?

Swanker: Children have a very low risk of developing a more severe corona infection. The data situation on Long Covid in children is not that good – but we know from other types of viral infections that long-term consequences only occur in adolescence. And the vaccine is approved for young people.

Children also do not spread the infection as much as adults. You can get infected, of course – but the major “superspreader” outbreaks are only seen from the age of 16.

tagesschau.de: Hamburg now wants a so-called 2G model Introduce the vaccinated and recovered clearly – for example at events and restaurant visits. Does it make sense to abandon the 3G rule, which is quite widespread across Europe?

Swanker: You simply have a high residual risk with the rapid tests: To be “tested” is a very volatile and uncertain status from a virological point of view: it lasts for a maximum of 24 hours and the rapid tests are simply imprecise for those infected without symptoms. They only show 50 to 60 percent correctly whether someone is infected.

The rule “recovered or vaccinated” gives significantly more security and is easier to implement. Having to check all three “Gs” at the same time at larger events, for example, also means much more effort for the organizers. So I can understand this decision very well.

Infections in vaccinated people are often mild

tagesschau.de: In addition to the safety aspect, do you also believe in an educational effect, so that those who do not want to vaccinate will change their minds after all?

Swanker: I’m not a psychologist to be able to judge that. But you can look in other countries to see what happened there after the introduction of the 2G rule. In the USA, for example, such restrictions have actually resulted in significantly more people being vaccinated.

tagesschau.de: What can we expect in autumn when even more people are fully vaccinated by then? Can there still be incidence values ​​of several hundred, as some have already extrapolated?

Swanker: In any case, the vaccination rate will have a significant effect on the incidence. We know from Bavaria that last week the incidence was 40 in the unvaccinated – and four in the vaccinated! There is a clear difference, but the infection is not at “zero” in people who have been vaccinated either, you have to know that. The infections of those who have been vaccinated are usually very mild, in half of the cases even completely asymptomatic – but not always.

“Precautions must be maintained”

With the very infectious Delta variant, we will certainly see a significant increase in the incidence of infections again. On the one hand, this can only be influenced by the vaccination quota – and on the other hand, we have to continue to adapt our behavior. In other words: precautionary measures such as wearing masks will have to be maintained through autumn and winter, be it indoors with many people or on public transport.

tagesschau.de: When would a partial lockdown be necessary again – or do we no longer have to think about it?

Swanker: From when – that is a difficult and ultimately a political question. One can consider offsetting the incidences against the vaccination rates and the burden of disease. Then one could tolerate two to three times higher incidences at the current vaccination rate. The more we vaccinate, the better the rate gets. But we couldn’t suddenly tolerate an incidence of 1000, then the hospitals would probably be too stressed – but we are now measuring that separately.