A new intratypic variant of coxsackie B6 virus

Abstract

Reference antisera to established prototype enterovirus strains failed to neutralize three enterovirus isolates which were recovered from clinical specimens. Hyperimmune rabbit serum to one of the isolates neutralized the prototype coxsackie B6 strain as well as t~he three isolates. Kinetic neutralization tests confirmed the one-way cross reaction and it was concluded that the isolates are prime strains of eoxsackie B6 virus, a virus for which antigenic variants have not been reported so far. Since the co~saekie B 6 serotype has never been encountered in Ontario, the prevalence of antibodies to the isolate was studied by e~amining 382 human sera from our collection of patients' sera. Approximately 10 per cent of the sera contained antibodies to the isolate but cross reactivity with the prototype strain was seen only when the titre against the prime strain was very high.