The worldwide spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the associated infectious coronavirus disease (COVID-19) has posed a unique challenge to medical staff, patients and their families. Patients with cancer, particularly those with haematologic malignancies, have been identified to be at high risk to develop severe COVID-19. Since publication of our previous guideline on evidence-based management of COVID-19 in patients with cancer, research efforts have continued and new relevant data has come to light, maybe most importantly in the field of vaccination studies. Therefore, an update of our guideline on several clinically important topics is warranted. Here, we provide a concise update of evidence-based recommendations for rapid diagnostics, viral shedding, vaccination and therapy of COVID-19 in patients with cancer. This guideline update was prepared by the Infectious Diseases Working Party (AGIHO) of the German Society for Haematology and Medical Oncology by critically reviewing the currently available data on these topics applying evidence-based medicine criteria., Competing Interests: Conflict of Interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: N.G. reports receiving personal fees from MSD, Roche, Pfizer; grants from BMS, Karyopharm, outside the submitted work. SCM reports grants from University of Cologne (KoelnFortune), DMyKG, DZIF, personal fees from Octapharma, outside the submitted work. YK reports personal fees from GILEAD Sciences, grants, personal fees and other from MSD SHARP & DOHME, outside the submitted work. GB reports grants from The German Federal Ministry of Research and Education, The German Federal Ministry of Health, personal fees from Jazz Pharmaceuticals, MSD, NewConceptOncology, outside the submitted work. CL reports non-financial support from Jazz Pharmaceuticals, Neovii, outside the submitted work. MH reports personal fees from Amgen, Janssen, Celgene, Sanofi, Takeda, outside the submitted work. MBB is the PI of the COVACTA Trial at LMU. OAC is supported by the German Federal Ministry of Research and Education, is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - CECAD, EXC 2030 - 390661388 and has received research grants from Actelion, Amplyx, Astellas, Basilea, Cidara, Da Volterra, F2G, Gilead, Janssen, Medicines Company, Melinta, Merck/MSD, Octapharma, Pfizer, Scynexis, is a consultant to Actelion, Allecra, Amplyx, Astellas, Basilea, Biosys, Cidara, Da Volterra, Entasis, F2G, Gilead, IQVIA, Matinas, MedPace, Menarini, Merck/MSD, Mylan, Nabriva, Noxxon, Octapharma, Paratek, Pfizer, PSI, Roche Diagnostics, Scynexis, and Shionogi, and received lecture honoraria from Astellas, Basilea, Gilead, Grupo Biotoscana, Merck/MSD and Pfizer. PK has received non-financial scientific grants from Miltenyi Biotec GmbH, Bergisch Gladbach, Germany, and the Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany, and received lecture honoraria from or has been advisor to Akademie für Infektionsmedizin e.V., Ambu GmbH, Astellas Pharma, Gilead Sciences GPR Academy Ruesselsheim, MSD Sharp & Dohme GmbH, Noxxon N.V., and University Hospital, LMU Munich, outside the submitted work. ES reports lecture honoraria from Gilead, outside the submitted work. M.v.L.T. reports personal fees from Celgene, Gilead, Chugai, Janssen, Novartis, Amgen, Takeda, BMS, Medac, Oncopeptides, Merck, CDDF, Pfizer, 4DPharma, Shionogi; grants from BMBF, Deutsche Jose Carreras Leukämie-Stiftung, IZKF Jena, DFG, Novartis, Gilead, Deutsche Krebshilfe, Celgene, outside the submitted work. RS, MR, MK, MS, HW, HHH, BW have nothing to disclose., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)