Phylogenetic analysis of Swiss SARS-CoV-2 genomes in their international context

This phylogeny shows evolutionary relationships of SARS-CoV-2 viruses from the ongoing novel coronavirus COVID-19 pandemic with a particular focus on Switzerland. We aim to include as many genomes from Switzerland as possible. In addition, we include virus genomes from other European countries and to lesser extent from the rest of the world to provide phylogenetic context. This context is important to understand how different outbreaks are connected and how the virus might have spread around the globe. We note, however, that direct linkage on the tree does not necessarily mean there exists a direct epidemiological link. Sampling of viral genomes is very incomplete and heterogeneous and mutations occur on average only every two weeks. Extended periods without mutations are therefore not uncommon and direct links or directionality cannot be inferred from the tree alone.

For background on genomic epidemiology, have a look at the introductory material on We also provide a narrative explaining the analysis of the Swiss data. To explore the data in greater depth, visit

The data from Switzerland was contributed by the following groups:

All data we use (Swiss and international) are deposited in GISAID.

We gratefully acknowledge the authors, originating and submitting laboratories of the genetic sequence and metadata made available through GISAID on which this research is based.