IL6 and infection: For infection of CA (B.1.1.7) or SA (B.1.351) variant, multiple cytokines and chemokines in lung and liver were critical to differentiate from those induced by early WA (614D) or NY (614G) strain, including pulmonary MIP-2 (VIP score 1.46), IL-6 (VIP score 1.04), IL-1β (VIP score 0.88), TNF-α (VIP score 0.78) and MIP-1β (VIP score 0.15), and hepatic MIP-1α (1.74), IL-13 (VIP score 1.56), MIP-2 (VIP score 1.39), IL-6 (VIP score 1.38), IFN-β (VIP score 1.30) and IFN-α (VIP score 0.52).