Objective To explore the effect of cancer related anemia on the abundance of SARS-CoV-2 specific memory CD8+T cells in peripheral blood.Methods A total of 34 HLA-A*11∶01 positive patients with middle-and late-stage tumors admitted in the Rocket Force Medical Center of PLA from June to July 2023 were enrolled in this study.According to hemoglobin(HGB)level,they were divided into non anemia group(≥120 g/L,n=14),mild anemia group(90～120 g/L,n=14),and moderate to severe anemia group(＜90 g/L,n=6).After their peripheral blood mononuclear cells were isolated,memory CD8+T cells were stimulated by the epitopes of SARS-CoV-2 and then expanded.Positive epitopes were screened using enzyme-linked immunosorbent spot(ELISP OT)assay,and then MHC-peptide Tetramers were constructed.The proportion and number of Tetramer+cells and the number of ELISPOT spots were detected in the expanded cells to reflect the abundance of SARS-CoV-2 specific memory CD8+T cells.The relevance of patients'HGB level with the proportion and number of Tetramer+cells and the number of ELISPOT spots was analyzed.The differences of the proportion and number of Tetramer+cells and the number of ELISPOT spots was analyzed in different groups.Results Among the 34 patients,there were 25 males and 9 females,at an age range of 36～78(median 57)years.The proportion and number of Tetramer+cells and the number of ELISPOT spots were positively correlated with HGB level(P＜0.05).The proportion and number of Tetramer+cells and the number of ELISPOT spots were significantly decreased in patients with moderate to severe anemia than the non anemia patients(P＜0.05).Conclusion The abundance of SARS-CoV-2 specific memory CD8+T cells in peripheral blood is positively correlated with patients'HGB level,indicating that CRA may increase the susceptibility of patients to viruses by reducing the abundance of memory CD8+T cells in peripheral blood.