Antigenic drift in the course of subacute sclerosing panencephalitis (SSPE).

Neutralization kinetics study performed with measles virus and canine distemper virus (CDV) antigens revealed differences in the behaviour of antibodies contained in the cerebrospinal fluid (CSF) samples from SSPE patients. Evident differences were observed both between samples from various patients and between CSF samples collected from the same patient in the course of the disease. Hyperimmune sera could be obtained in rabbits and guinea pigs by initial immunization with unpurified measles of CDV antigen, followed by heterologous inoculation of the animals with the other antigen. The data obtained are interpreted as arguments for a pathogenic mechanism consisting in an antigenic drift occurring in the course of SSPE.