SARS-CoV-2 vaccine response by absolute lymphocyte count and treatment history. Spike antibody serologic response value by RBD immunoassay (y-axis) plotted against absolute lymphocyte count and treatment history (x-axis). Each circle corresponds to an individual patient (n = 34). P = .001 by Kruskal–Wallis rank-sum test comparing the distributions of the continuous data among the 4 groups; P < .001 for Wilcoxon rank-sum test comparing 2 groups (treatment-naïve patients with ALC ≤ 24 000/µL vs ALC > 24 000/µL and/or current or prior therapy). Patients enrolled in both cohorts were included in this analysis. Two patients without quantitative spike antibody serologies were not included in the plot.