Transitory appearance of type 2 neutralizing antibody in patients infected with type 1 poliomyelitis virus.

Neutralizing antibodies for Type 2 (Lansing) poliomyelitis virus were tested periodically in a group of 18 patients from whom Type 1 poliomyelitis virus was recovered. Data for homotypic neutralizing antibodies and Type 2 complement-fixing antibodies were also available on the majority of these patients. The results indicated that Type 2 neutralizing antibodies first appeared or significantly increased in titer in 11 of the 18 patients during the first 2 to 4 weeks after onset. In most patients the Type 2 neutralizing antibody either completely disappeared at 3 months (in one patient between 2 and 4 weeks) or dropped in titer, while the Type 1 or homotypic antibody persisted in high titer. These results are interpreted as indicating that the Type 1 and Type 2 poliomyelitis viruses share a common antigen, and that the heterotypic anti-body response is transitory while the homotypic neutralizing antibody persists for a longer time.