“Currently, Covid-19 is primarily a disease of the unvaccinated”
Corona and no end: will Germany soon be hit by the fourth wave?
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After what felt like a corona-free summer, the RKI is reporting worrying figures again. How can the continuously increasing incidences be explained? What role do schools and return travelers play? The age distribution of the new infections is telltale.
Lthe nationwide incidence stagnated at a low level, now the numbers are rising again. 9,280 new corona infections were reported to the Robert Koch Institute (RKI) from Thursday to Friday. For the third time in a row, over 8,000 cases have been reported, the nationwide 7-day incidence has risen to almost 50 – similar values were last seen at the end of May.
Is the dreaded fourth wave now being announced and will it necessitate restrictions and measures similar to those that Germany already had to get to know? No one can definitely say that at the moment, says Hajo Grundmann. At the Institute for Infection Prevention and Hospital Hygiene at the University Clinic in Freiburg, which he heads, he himself developed a model to provide the health authorities with prognoses on the course of incidence and the occupancy of intensive care beds. R-value, vaccination rate, contact behavior of the population – all of this is included in the calculation. But because too many unpredictable factors influence this curve, he says, his model can only make reasonably reliable predictions for the next 30 days. And even those turn out differently every day, as soon as, for example, the R value only changes by a few decimal places.
For the corresponding date, September 16, his computer predicts more than 20,000 new infections every day based on the currently available data. For the intensive care physicians, this would mean that they would then have to care for more than 1,500 patients. At the height of the second wave it was over 5,000 at times.
According to the expert, it is not to be expected for the time being that anything will change in the exponential increase in incidence. This is mainly because the main causes will not go away. First and foremost, the spread of the delta variant should be mentioned here. 98 percent of new infections are currently caused by it, and it is almost twice as infectious as the previous virus. At the beginning of June it was no more than ten percent, a month later the incidence values began to climb again.
Reason number two, Grundmann suspects: The school holidays in the northern federal states came to an end two or three weeks ago. With a seven-day incidence of 51.2, Schleswig-Holstein, for example, is well above the national average. A country that often reported single-digit values in spring and summer. The clear orientation of the new infection rates along national borders also speaks for the influence of the school holidays factor. Berlin, Hamburg, North Rhine-Westphalia, Schleswig-Holstein: The redest regions on the map are those with an early holiday end.
What contribution return travelers who bring viruses from other countries to the current infection situation will probably become apparent in the next few days. If the increase in the incidence value stagnates for a short time, its influence actually becomes noticeable. Because most of them do not pass on their souvenirs to many people. If the curve climbs exponentially upwards unaffected, the pathogen is already so widespread in Germany that the holiday return factor hardly has any effect – provided those affected do not bring in any new risk variants.
The age distribution of the new infections is also telltale. “Currently, Covid-19 is primarily a disease of the unvaccinated,” says the infection expert. According to the RKI weekly report, it is primarily the 15 to 24-year-olds and – to a lesser extent – the adjacent age groups who are currently driving the infection process. In the group of 20- to 24-year-olds, the seven-day incidence of 94 to 100,000 young adults has now arrived. There are 87 among 15 to 19 year olds, and 69 among children between 10 and 14 years of age. For comparison: the authorities report single-digit values for senior citizens. The boys are not only the section of the population that has the lowest vaccination rate, but also those that are on average the most mobile and sociable. This makes them the ideal carriers of the pathogen. Whether other social factors such as school, university, job also play a role here cannot be deduced from the new RKI values.
“There is no better antidote to the pathogen than vaccination,” says Grundmann. In the meantime, however, the daily number of first injections has reached the level of mid-February, when vaccines were still missing everywhere. The rate of double vaccinations is an unsatisfactory 58 percent. “The comprehensible” corona fatigue “in the population is also not helpful,” said the expert. Because this also has a strong impact on the course of the pandemic through the changed mobility and contact behavior.
Are we facing the next lockdown? “I hope not,” says the expert. “And as an optimist, I assume that many are now becoming more cautious and the willingness to vaccinate is increasing.” Otherwise, the newly gained freedom may quickly be over.
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