ABSTRACT
Most of the CFs are composed of up to 100 identical structural subunits and several of the CFs also express distinct tip proteins. Both the structural proteins and tip proteins have been considered as candidate immunogens (10,12,13). Recent studies have also revealed that antibody preparations against whole CFA/I fimbriae as well as the CFA/I tip protein in milk formulas have afforded significant protection in human volunteers challenged with virulent CFA/I ETEC (16). Immunization using recombinantly produced CF tip proteins has also afforded significant protection against challenge with ETEC expressing corresponding CFs in primates (Savarino et al., unpublished).
