WHO COLLABORATIVE STUDIES ON ENTEROVIRUS REFERENCE ANTISERA

Abstract

The studies were designed to appraise the specificity of immune serum prepared in horses against 5 representative prototype enteroviruses (poliovirus 1, cox-sackieviruses A9 and B3, and echoviruses 4 and 11). Tests for neutraliz. ing antibody were performed not only against the homologous viruses, but also against a battery of heterotypic picornaviruses, comprising 63 enteroviruses, several rhinoviruses, and 3 reoviruses. Each serum sample represented a pool of the individual bleedings taken from groups of 5 or 6 horses before and after immunization with each virus antigen (except echovirus 4, for which 3 animals were immunized). The results showed that, whereas the homologous titres of the antisera (poliovirus 1, coxsackieviruses A9 and B3, echoviruses 4 and 11) were found to be within a useful range (700-8000), heterotypic antibodies of significant titre were not detected. All corresponding pre-inoculation sera were negative. The specificity of the haemagglutination-inhibiting antibody of the coxsackievirus B3 and echovirus 11 antisera was also demonstrated. This accumulated information played a major role in a decision to prepare in horses antisera to the rest of the enterovirus group.