Antibody Response in Monkeys Following Oral Administration of Poliomyelitis Virus

Summary Following the oral administration of poliomyelitis virus to cynomolgus, rhesus and cercopithecus monkeys—some of which had been tonsillectomized to render them more susceptible to infection—tests for neutralizing antibodies were carried out on matched serum samples. Of 44 monkeys used in these experiments, the sera collected prior to the feeding of virus, gave negative tests for antibodies in 43. Of 17 monkeys developing the experimental disease, antibodies were found in 13 on the first day of paralysis. Of 27 monkeys remaining apparently healthy after the virus feeding, antibodies were found in 10 in sera collected 4 to 5 weeks after exposure to virus. The medullas and spinal cords of such monkeys with positive sera were examined histologically and found to be free of poliomyelitic lesions. The rapid antibody response following oral administration is different from the slow response observed in monkeys inoculated intracerebrally. Antibodies which developed in the course of these feeding experiments appeared to be specific for poliomyelitis virus as they failed to react with lymphocytic choriomeningitis virus and influenza virus. When monkeys were fed mouse encephalomyelitis virus (FA strain) which is non-pathogenic for primates, they failed to respond with antibodies to this virus. Together with the above data this suggests that early antibody production as well as antibody production in asymptomatic monkeys fed poliomyelitis virus is the result of infection of tissue outside the central nervous system.