Importance of Optimum Amounts of Virus to Demonstrate Neutralizing Antibody Rise in Convalescent Poliomyelitis Sera.

Abstract

Summary The formation of neutralizing antibodies against their own virus was studied in 38 poliomyelitis patients. In the sera of 35 (92%), 5-fold or greater antibody increases were demonstrated. Twenty-nine (76%) exhibited rises between 10 and 500-fold. The average dose of virus used in separate tests was about 3 log dilutions. “Box” neutralization tests revealed that little or no antibody increase was demonstrable in the zones of antibody or virus excess. Substantial antibody rises were obtained in the middle zones, when between 2.5 and 4.6 log dilutions of virus were used. A similar trend of antibody increase was found with homotypic virus studied in two individuals. These results seem to indicate a relation between increase in neutralizing antibody and concentration of virus in the test. The mechanism by which this phenomenon operates is not understood but it appears to have both fundamental and practical implications.