The difference of this value with the plateau of neutralizing activity of hospitalized individuals was highly significant (p < 10 –7 by Z-test, and p < 10 –4 by Wilcoxon test as described in methods; Fig. 2 B), and reflects the different distribution (p = 0.0003, Chi-square test) of individuals with undetectable (< 20), low (20–100), medium (100–1000) or high (> 1000) neutralization titers in the non-hospitalized and the hospitalized groups (Fig. 2 C).
Kinetics were similar for severe and non-severe individuals, while ICU participants showed a trend towards faster and higher development of neutralizing activity; however, differences were not statistically significant.
Similarly, unbalanced gender distribution among groups seems to be unrelated to neutralization titer, although barely significant differences were observed when maximal titers of neutralization were compared (Fig. 3 C), the kinetics and plateau of female and male participants were similar when a longitudinal analysis was performed (Fig. 3 D).