*p-value derived from Kruskal-Wallis' test and refers to the comparison between whole the groups
**p-value is derived from the Mann-Whitney U test and refers to the comparison between control and moderate disease groups.
***p-value is derived from the Mann-Whitney U test and refers to the comparison between control and severe/critical disease groups.
****p-value is derived from the Mann-Whitney U test and refers to the comparison between moderate disease groups and severe/critical disease groups.