»In order to put the wastewater results in better perspective, it was particularly important that the locations of the wastewater treatment plants also have a large overlap with the »SentiSurv« cohorts. We were involved in the discussions with the state government and were able to put this forward as a proposal. This is certainly not something that happens very often anywhere in the world, such an optimal data situation that has brought us really great results,« says a delighted Neele Leithäuser. »To exaggerate a bit, we have found the magic conversion factor for prevalence, at least for this period, which nobody believed in at the beginning.« Researchers are learning from the »SentiSurv« and wastewater data. The detailed results are recorded, for example, in the paper »Estimating the COVID-19 Prevalence from Wastewater«. »However, we also know that the calibration can no longer take place if the cohort data is no longer available, then the wastewater data can be more off the mark again, especially with new variants, but we have the reference points,« summarizes Mohring.