Fig. 2: Association of the ID50 neutralization titer with COVID-19 severity.

Violin plot depicting the neutralizing activity, measured within 6 months from the first positive SARS-CoV-2 PCR, in HM patients grouped according to COVID-19 severity. Bars represent median (thick line) and interquartile range (dotted line). Statistical analysis was performed by Kruskal–Wallis and Dunn’s tests.