THE USE OF ANTIPOLIOVIRUS MONOCLONAL-ANTIBODIES AS AN IMPROVED SAFETYTEST FOR ORAL LIVE POLIOMYELITIS VACCINE

Almost all the individual preparations of poliovirus type 3 specific m onoclonal antibodies showed high neutralizing antibody titres against low-titre Sabin type 3 virus with a titer of 10(2) CCID50/25 mu l. How ever, the preparations failed to neutralize high-titre vints at a titr e of about 10(7) CCID50/25 mu l (undiluted virus fluid). The use of po oled monoclonal antibodies, comprising two or move individual antibodi es, however, showed a high neutralizing activity for the high-titre vi rus suspension. The results indicate that the neutralization of high-t itre Sabin type 3 virus can be achieved by the use of pooled monoclona l antibodies when appropriate antibodies ave present. If seems likely that neutralization by these antibodies is achieved through the recogn ition of different neutralizing epitopes by specific antibodies. One o f the safety tests used during the production of oval poliomyelitis va ccine (OPV) is that which employs type-specific antipoliovirus rabbit sera to detect adventitious viruses in monovalent poliovirus fluid. It has, however, proved difficult to prepare sera of this nature which c an completely neutralize high-titre poliovirus having no cross-reactiv ity against other types of poliovirus. In our studies, pooled monoclon al antibodies showed a neutralizing activity against high-titre Sabin type 3 virus about 100-fold greater than that shown by rabbit antisera . Moreover, these antibodies appear to have two further important adva ntage for use in testing the safety of OPV: they showed no cross-neutr alizing activity against heterotypic polioviruses; and they showed no evidence inhibiting the propagation of a number of viruses of monkey a nd human origin.