Immune Response to Surface Protein A ofStreptococcus pneumoniaeand to High–Molecular‐Weight Outer Membrane Protein A ofMoraxella catarrhalisin Children with Acute Otitis Media

The immune response was evaluated in 11 children with Streptococcus pneumoniae and in 9 children with Moraxella catarrhalis otitis media. The age of the children had a range of 4-32 months. The mean IgG, IgM, and IgA antibody responses to surface protein A (PspA) of S. pneumoniae in sera from children at the acute and convalescent stages were 4864 versus 5831 ng/mL, P<.05, 1075 versus 3752 ng/mL, P<.05, and 67 versus 93 ng/mL, nonsignificant (NS), respectively. The mean IgG, IgM, and IgA antibody responses to the high-molecular-weight outer membrane protein (UspA) of M. catarrhalis in sera from children at acute and convalescent stages were 710 versus 935 mg/mL, NS; 1895 versus 2646 ng/mL, NS; and 121 versus 204 ng/mL, P<.05, respectively. These data show that PspA and UspA are immunogenic in children after otitis media.