Reproductive number

The effective reproductive number Re quantifies how many people are infected on average by an infected person. We provide the latest estimate of the effective reproductive number Re in Switzerland. This figure is updated daily with the latest available data from the FOPH. The Re estimates are available in csv format at https://github.com/covid-19-Re/dailyRe-Data.

The Re value which is calculated today reflects the infection dynamics of 10-13 days ago for Switzerland and 14-17 days ago for cantons, due to the delay between infection and positive test result. We perform new calculations whenever new data from FOPH is available. On Tuesday, Wednesday, and Thursday, this does however not result in additional days for which Re values are available due to weekend effects. Thus, on Friday, four additional days with Re values become available. The most recent Re value is marked with an asterisk in the figure.

IMPORTANT: In general, we note that the Re estimates for the last days may still be consolidated during subsequent days. This consolidation in particular occurs for small regions, during changes in the dynamics, and in case of small case numbers. For details on methods and caveats please see https://ibz-shiny.ethz.ch/covid-19-re-international/.

IMPORTANT FOR HOLIDAY SEASON: Please note that Re values based on confirmed cases over the holiday season may be underestimates due to possibly less testing during these days.

An overview of the current epidemiological situation based on the reproductive number Re and other indicators can be found here. More extensive updates of the epidemiological situation are published by the Science Task Force in the form of Policy Briefs.

More information and additional tools for the assessment of the epidemiological situation based on Re can be found here. In particular, we provide estimates of Re for individual cantons, larger Swiss regions, and other countries. These Re estimates, as well as the case numbers per country, are displayed on a world map. Additionally, we show estimates on the changes of Re following the introduction or release of interventions. Lastly, we display the estimated number of daily new infections based on the daily case data. This time course is used for the Re calculations. The results for Re are available as a .csv file.