A study comparing the concentrations of pneumococcal antibody serotypes 1, 3, 6, 14, 18, 19, and 23 in MEF and serum of 61 children with AOM found that, during the acute phase of disease, IgG and IgM were predominant in serum, whereas IgG, IgM, and IgA were all detected in MEF. The gene discussed is CD79A; the disease is infectious otitis media.