Further experiments on the adaptation of Mahoney, type 1, poliomyelitis virus to suckling mice.

Abstract

The Mahoney, Type 1, poliomyelitis virus had been through six to-and-fro monkey kidney-tissue culture and suckling mouse passages. Early paralysis was produced in groups of mice inoculated directly from infected tissue-culture fluid, but mouse-to-mouse passage failed to produce paralysis except in an occasional mouse. At the 7th tissue-culture mouse passage, the virus harvested from paralysed mice was inoculated into 100 mice. One mouse developed paralysis within 24 hr. From this mouse a variant of Mahoney virus was isolated which has now been through seventy-five mouse-to-mouse passages and produces paralysis in 90–100% of mice within 3 days.The authors would like to express their deep appreciation of Prof. A. Kipps' constant interest and encouragement.