A HIGHLY DIVERGENT ANTIGENIC SITE OF FOOT-AND-MOUTH-DISEASE VIRUS RETAINS ITS IMMUNODOMINANCE

The ability of a highly divergent antigenic site of foot-and-mouth dis ease virus (FMDV) of serotype C to elicit neutralizing antibodies has been evaluated in mice and rabbits, The viruses compared, FMDV C-S8c1 and HR, differ in a single amino acid replacement in their capsid prot eins, but represent two extreme antigenic specificities of the major a ntigenic site A of FMDV type C. Both, studies of cross-neutralization of homologous and heterologous virus, and fractionation of site A-spec ific antibodies by immunoaffinity chromatography suggest a similar imm unodominance of antigenic site A in FMDV C-S8c1 and variant HR. This i nformation is relevant to the formulation of synthetic peptide vaccine s that ideally should consist of mixtures of peptides representing sev eral antigenic specificities. These cocktail formulations may be requi red to control diseases caused by FMDV and, generally, by highly varia ble RNA viruses, since single specificity peptides may trigger selecti on of vaccine-escape viral mutants.