Coronavirus disease (COVID-19) in patients undergoing hematopoietic stem cell transplantation (HSCT) is a major issue. None of the published papers have reported data on the outcome of HSCT patients with COVID-19 according to the vaccination status and the short course of remdesivir (RDV). Therefore, we present the case of a 22-year-old man with relapsed testicular non-seminomatous germ-cell tumor who was diagnosed with COVID-19 during his first auto-HSCT. Our case report is the first one describing the efficacy of early RDV (and its anti-inflammatory effects that might counterbalance the negative effect of the recombinant human granulocyte-colony stimulating factors -rhG-CSF-) in the context of severe neutropenia following HSCT with the concomitant onset of COVID-19.