Immunogenicity of a killed E. coli 0111:K58 vaccine administered orally to children.

A killed E. coli 0111:K58 vaccine was administered by the oral route to 16 children ranging from 3 months to 7 years of age. The antibody response was measured at different times after the vaccination through the titration of agglutinating antibodies in serum and in fecal extracts, and the detection of specific IgA immunoglobulins in the intestinal content. All vaccines developed antibody response detectable both inserum and in fecal samples. Coproantibodies tended to appear earlier and to attain higher titers than circulating antibodies; they were all least in part IgA immunoglobulins, since the content of specific IgA in the fecal extracts was proportional to the agglutinating titer.