Characteristics of poliovirus type 3 strains after passage through monkey central nervous system.

Cercopithecus aethiops monkeys were inoculated intracerebrally with Sabin's type 3 polivoirus strain, and with strains isolated from subjects vaccinated with Leon 12a1b and from their contacts. Sample of brain, spinal cord, kidneys, lymph nodes, blood and spinal fluid were taken. From these materials, (except of kidneys) 23 poliovirus strains of type 3 were isolated. Genetic markers rct 40.3, rct 41, d and IST were determined for these strains. The changes observed in genetic markers of strains passaged through the cental nervous system (CNS) of monkeys are described.