Found an error?
Report now
The R-value was ubiquitous during the corona pandemic. But according to Empa researchers, it falls short. (archive image)
Keystone
A new mathematical model developed by Swiss researchers aims to better predict epidemics in the future. In the new model, the reproduction number, the R-value known from the coronavirus pandemic, is replaced by a reproduction matrix.
In tests with data from the coronavirus pandemic in Switzerland and Scotland, the model developed by researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa) was able to predict much more accurately when peaks in infection rates were reached, as the institute announced on Thursday.
The reproduction number R describes how many people an infected person infects on average. If R is greater than one, the number of cases increases exponentially; if R is less than one, it decreases. However, this figure is highly simplified. In reality, according to the researchers, not every person infects the same number of other people. Superspreaders with many contacts infect a disproportionately high number of people, while others infect hardly anyone.
This is taken into account by using a reproduction matrix. For their model, the researchers divided society into groups according to age. People between the ages of 10 and 25 have the most contacts.
According to the researchers, the R-value can predict the incidence of infection at the beginning of a pandemic. However, the peak of an epidemic or pandemic is usually lower than model calculations with the R-value would suggest, as the researchers explain.
The reason: the number of superspreaders in society is relatively small. If they are all infected, the spread of the disease slows down. Conventional models based on the reproduction number R do not take this slowdown into account.
The researchers led by Ivan Lunati presented the new model to the scientific community in the "Journal of the Royal Society Interface". While it works well for relatively small countries such as Switzerland and Scotland, it could have more problems for large countries, as the researchers admit. This is because it assumes that both the infections and the superspreaders are evenly distributed throughout the country. However, according to the researchers, the geographical distribution of the population and contacts between regions must also be taken into account in large countries.
23.01.2025, 09:42
