**2. Methods**

The literature search was conducted repeatedly between 16 March and 8 April 2020. We searched original papers, observational studies, case reports and meta-analyses published between 2019 and 2020, using two databases (PubMed, Google Scholar) with the search terms: [transplant OR immunosuppression] AND [COVID-19 OR SARS-CoV-2]. Further inclusion criteria were publications in English, French, German and Italian, and reference to humans. We also searched the reference lists of the studies encountered.
