Main text Patients with cancer are at high risk for severe clinical courses of COVID-19 and delays of antineoplastic treatment due to SARS-CoV-2 infections (). SARS-CoV-2 vaccinations were shown to be quite effective and well tolerated according to post-authorization data and real-life studies of hemato-oncological cohorts (). However, we ( Mair et al., 2022a Mair M.J. Berger J.M. Berghoff A.S. Starzer A.M. Ortmayr G. Puhr H.C. Steindl A. Perkmann T. Haslacher H. Strassl R. et al.