WHO collaborative studies on enterovirus reference antisera.

The research article centers on a collaborative study led by WHO International Reference Centre for Enteroviruses. The study’s objective was to verify the specificity of antiserums produced in horses against five types of enteroviruses. The study found that while the antisera had relevant homologous titres, they did not exhibit heterotypic antibodies of substantial magnitude, proving their specificity to particular strains of viruses.

Research Context and Process

• The research work was undertaken cooperatively by WHO International Reference Centre for Enteroviruses, WHO monitoring laboratories, regional reference centres, and several other laboratories. This collaboration aimed to facilitate a broad testing program for equine antisera, which are immune serums prepared in horses against enteroviruses.
• The focus of the study was essentially on five prototype enteroviruses, namely, poliovirus 1, coxsackieviruses A9 and B3, and echoviruses 4 and 11.
• The researchers tested for neutralizing antibodies not only against these specific viruses but also against a range of different picornaviruses. This extensive group consisted of 63 enteroviruses, several rhinoviruses, and three reoviruses.
• The serum samples taken for testing was a pooling of individual blood extracts from groups of five or six horses, which were immunized with each virus antigen.

Research Findings

• The results of the conducted tests revealed that the “homologous titres” of the antisera, essentially titres against the corresponding viruses, were found in a useful range of 700 to 8000.
• On the other hand, heterotypic antibodies (antibodies responding to different antigens) of significant titre were not discovered. Such a finding suggests that the antisera were highly specific for their targeted viruses and showed little non-specific response to other types of viruses.
• The researchers further attested to the specificity of the antisera. All samples taken before the horses were inoculated with the viruses were found to be negative.
• Specificity was also displayed in the haemagglutination-inhibiting antibody (a type of antibody that prevents viruses from clumping red blood cells together) of the coxsackievirus B3 and echovirus 11 antisera.

Implications and Further Research

• The findings from this study are instrumental and led to the decision to prepare antisera in horses for the rest of the enterovirus group.
• The process of cooperative testing for other enterovirus equine antisera is reportedly in progress, indicating it is part of an ongoing, larger scale study.

The study provides valuable data on the specificity of equine-derived antiserums and their possible application in medical research or treatments targeting relevant viral pathogens.