Community-acquired respiratory viruses (CARV), such as influenza-, parainfluenza- or respiratory syncytial virus, pose a significant threat to immunocompromised patients with cancer. Following the COVID-19 pandemic, SARS-CoV-2 has now joined the ranks of endemic respiratory viruses and continues to be a cause of significant morbidity and mortality in patients with cancer. Strategies to protect this vulnerable patient population both by prevention of infection and by early therapeutic intervention in case of infectious disease are therefore of utmost importance. This guideline provides updated evidence-based recommendations on diagnosis, prophylaxis and treatment of CARV infections including COVID-19 in patients with solid tumors or hematologic malignancies to support clinicians in offering optimal care. The guideline is based on a systematic review of currently available data and was developed until the beginning of 2025 by an expert panel of the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO).
