IGHG3 and infection: We show that a greater presence of Th2-associated IgG2 and IgG4 (resulting in a smaller skew in IgG subclass imbalance towards Th1-associated IgG1 and IgG3) in the early phase of infection is associated with severe disease, while a stronger skew towards Th1-associated IgG1 and IgG3 may be important in controlling disease progression and clinical recovery.