LAUSR

AIM This study examined the serum antibody response of coronavirus disease 2019 (COVID-19) vaccines in solid and hematologic cancer patients undergoing chemotherapy. Levels of various inflammatory cytokines/chemokines after full vaccination were analyzed. METHODS Forty-eight patients with solid cancer and 37 with hematologic malignancy who got fully vaccinated either with severe acute respiratory syndrome coronavirus 2 messenger RNA (mRNA) or vector vaccines or their combination were included. After consecutively collecting blood, immunogenicity was assessed by surrogate virus neutralization test (sVNT), and cytokine/chemokines were evaluated by Meso Scale Discovery assay. RESULTS Seropositivity and protective immune response were lower in patients with hematologic cancer compared to those with solid cancers, regardless of vaccine type. Significantly lower sVNT inhibition was observed in patients with hematologic cancer (mean [SD] 45.30 [40.27] %) than in those with solid cancer (mean [SD] 61.78 [34.79] %) (p = 0.047). Heterologous vector/mRNA vaccination was independently and most markedly associated with a higher sVNT inhibition score (p < 0.05), followed by homologous mRNA vaccination. The mean serum levels of tumor necrosis factor α, macrophage inflammatory protein (MIP)-1α, and MIP-1β were significantly higher in patients with hematologic cancers compared to those with solid cancers after the full vaccination. In 36 patients who received an additional booster shot, 29 demonstrated increased antibody titer in terms of mean sVNT (%) (40.80 and 75.21, respectively, before and after the additional dose, p < 0.001). CONCLUSION Hematologic cancer patients receiving chemotherapy tended to respond poorly to both COVID-19 mRNA and vector vaccines and had a significantly lower antibody titer compared to those with solid cancers.