Immunity in Monkeys Recovered from Paralytic Attacks of Poliomyelitis

Abstract

Summary: Monkeys recovered from paralytic attacks of poliomyelitis, induced by six different strains of virus, were subsequently inoculated by the intracerebral route with homologous and heterologous strains. Of 149 animals tested 61 per cent exhibited complete immunity and an additional 30 per cent partial immunity. The death-rate of the series was 9 per cent while 50 per cent would be the estimated death-rate in a similar series of animals receiving first injections with the same strains of viruses. On the whole a greater degree of immunity was observed in recovered animals when tested with a homologous strain than when tested with a heterologous strain. Variations in the resultant immunity to different strains of virus are noted, the percentage ranging from 47 per cent in one strain to 86 per cent in another. Neutralization-tests were performed on 100 of the animals in the series and correlation between the neutralization- and immunity-tests was observed in only 50 per cent of the animals.