IMMUNOLOGIC CLASSIFICATION OF POLIOMYELITIS VIRUSES

Abstract

This is one of a series of papers on the typing of strains of poliomyelitis viruses. 67 strains of poliomyelitis viruses were studied by the method of neutralizing prototype viruses with antiserums produced by vaccinating monkeys with unknown virus mixed with a mineral oil adjuvant. 45 of the 67 strains were readily classified. 36 were Type 1, 5 were Type 2 and 4 were Type 3 strains of poliomyelitis viruses. 21 strains could not be classified by the methods and criteria used. Serums prepd. with these strains were studied in mouse and tissue culture neutralization tests. Using these methods to determine neutralization indices and serum dilution endpoints, 16 additional strains were assigned to a specific type. The 5 remaining strains showed heterotypic overlap. Serum dilution endpoints in neutralization tests provided information which permitted final classification of these strains in a single type. The problem of heterotypic serologic overlap is discussed in regard to the presence of components in normal monkey serums which neutralizes one or more of the 3 known types of poliomyelitis viruses; or to the occurrence of common antigens in the mosaic of some strains of poliomyelitis viruses.