The end of the 2019/2020 influenza season was already registered in early summer 2020, and in the following season. There was an nearly complete absence of influenza. So far, the sometimes strict Covid-19 containment measures with contact restrictions and the obligation to wear a mask have been mentioned as reasons. This study looks for further reaseons and from several perspectives in order to develop strategies for a representative recording of influenza cases derive. In contrast to influenza A/B, the other viral respiratory pathogens (adenovirus, parainfluenza virus and RS virus) do not show any significant reduction. From 2020, the number of reports of respiratory infections to the RKI increased from an average of 300,000 annual reports by 2019 to 1,985,985 reports in 2020, over 5,453,017 reports in 2021 and to 29,681,158 in 2022. On the other hand cases of incapacity to work due to respiratory infections fell from 31.0% in 2019 to 15.3% in 2021. Influenza-specific diagnoses (ICD: J10.1-3) were encrypted 33,727 times in 2021, in 2020 there were still 109,846. The reduction in influenza A and B from 2020 as a result of the comprehensive Covid-19 control measures, including the obligation to wear masks, cannot be considered a major reason; rather, the aspect of underreporting of influenza cases plays a significant role. Therefore, the reporting quantity of the sentinal practices should be considered and the recording of incapacity diagnoses should be taken into account.