CD79A and infection: If the IgG level is around 36.3 S/CO (IgA, 3.1 S/CO), then the individual may be in the acute phase of the infection, and if the IgG level reaches 88.5 S/CO (IgA, 10.1 S/CO), then he or she may be in the convalescent phase of the infection, or 3 to 4 weeks postinfection.