Fig. 3.

Boxplots describing neutralizing antibody (NAb) titer levels measured at day 0, 30, 90 and 180 since hospital admission. The mean days since symptom onset at admission was seven days and is added to the sampling time points in the figures to describe NAb titers in relation to symptom onset. All titers are presented in log₂ scale. A Boxplots describing log₂ NAb titers for all measurements taken at each sampling time point. Blue dots represent measurements from patients with high disease severity while red dots represent measurements from patients with low disease severity. B Comparison between vaccine-induced NAb titer responses at day 187 and NAb titer responses following natural infection without prior vaccination at day 37 since symptom onset. The blue boxplot represents measurements from vaccinated patients while the red boxplot represents measurements from non-vaccinated patients. Patients with high disease severity are marked with a triangle while patients with low disease severity are marked as dots. Mann–Whitney U tests were performed to test the null-hypothesis. *** = P < 0.001, ** = P < 0.01, * = P < 0.05, Ns Not significant