Fig. 1. Humoral and T cell responses in HCT recipients.
A Humoral and T cell responses after the second vaccination dose as compared to the first dose in HCT recipients. The red and blue dotted lines in the left graph indicate the 30% and 50% threshold above which CoV-2-NAbs are considered positive or highly protective, respectively. The blue dotted line in the middle graph indicates the threshold above which T cell response was considered positive. Median with 95% CI is shown. ****p < 0.0001, **p = 0.002. B CoV-2-NAbs and spike-STs after the second dose in healthy subjects, auto- and allo-HCT recipients, as well as the allo-HCT subgroups, on and off immunosuppression. The red and blue dotted lines in the left graph indicate the 30% and 50% threshold above which CoV-2-NAbs are considered positive and have been associated with clinically relevant viral inhibition, respectively. The blue dotted line in the right graph indicates the threshold above which T cell response was considered positive. Median with 95% CI is shown. ****p < 0.0001, ***p = 0.0005, **p = 0.0044. C Humoral protective immune responses after the 1st and 2nd vaccination dose in allo-HCT patients. Each line represents a single allo-HCT patient. The red dotted line indicates the 30% threshold above which CoV-2-NAbs are considered positive. D Association of circulating CD3+ cells <1000/μl with neutralization capacity and levels of spike-STs. Median with 95% CI is shown. **p = 0.0029, *p = 0.0292. HCT hematopoietic cell transplantation, Auto-HCT autologous HCT, Allo-HCT allogeneic HCT, CoV-2-NAbs neutralizing antibodies against SARS-CoV-2, spike-STs SARS-CoV-2 spike-specific T cells.