Fig. 2

Kaplan–Meier curve for a spike protein antibody titer ≤ 137 as an event (comparison of albumin values ≥ 3.5 g/dL versus < 3.5 g/dL). An antibody titer of 137 U/mL was assumed to be enough. Censored cases were shown as diamond-shaped marks. p < 0.05 log-rank test, p < 0.05 for generalized Wilcoxon test