FURTHER STUDIES ON THE KINETIC SERUM-NEUTRALIZATION (McBRIDE) TEST FOR POLIOVIRUSES

Abstract

Groups of 12 roosters were immunized with four type 1 poliovirus strains, Sabin's reference, one "vaccinee", one "vaccine-contact", and one "wild" strain, respectively. Sera were collected 1 week after the third, the fifth, and the seventh immunizing dose and tested simultaneously in the McBride antigenic test against the four virus strains used for immunization and against another "wild" strain. The immunization schedules of five or seven doses of virus inoculum resulted in specific sera of high antibody titers and were found suitable for kinetic neutralization studies. The statistical analysis of the test results demonstrated that antigenic differences among virus strains accounted for the largest single source of variation, and although the variation attributable to individual roosters was significant, it was small in comparison with that due to virus strain differences. These data indicated that a group of four roosters should be immunized with a single virus strain using five or seven doses; the mean value of the neutralization rate constants of the four individual antisera will well characterize the intratypic antigenic differences between virus strains.