Active Immunization Against Acute Anterior Poliomyelitis with Ricinoleated Vaccine
Authors: Kolmer John A. , Rule Anna M. 
Published: January 2023

Summary
Of 80 rhesus monkeys given 5 to 10 subcutaneous injections of ricinoleated vaccine in doses varying from 0.05 to 1 cc. per kilogram, 61 or 76 per cent were found completely protected when inoculated intracerebrally with 0.5 cc. of 5 per cent virus, while all of 17 unvaccinated controls developed paralysis in 5 to 8 days. Among the animals given 0.05 to 0.4 cc. per kilogram, 64 to 75 per cent were found protected, while doses of 0.5 and 1 cc. completely protected 93 to 100 per cent of a group of 21 animals. Of 7 additional monkeys given 5 subcutaneous injections in doses varying from 0.1 to 1 cc. per kilogram, 5 were found protected when inoculated intranasally two weeks later with 0.5 cc. of 10 per cent virus (two installations) while a control developed complete paralysis. Of 43 animals given 5 to 10 intracutaneous injections of the vaccine in doses varying from 0.05 to 0.5 cc. per kilogram, 33 or 77 per cent were found completely protected when inoculated intracerebrally with the same dose of virus, while all of the same 17 unvaccinated controls developed paralysis in 5 to 8 days. Intracutaneous injections of the vaccine, therefore, engender a higher degree of immunity than subcutaneous injections since doses of 0.1 and 0.25 cc. per kilogram immunized 80 to 94 per cent of animals, while similar doses by subcutaneous injection immunized from 73 to 75 per cent. Effective immunization with ricinoleated vaccine requires the administration of vaccine containing sufficient living virus to produce paralysis of monkeys inoculated intracerebrally with 0.3 cc. Furthermore, we have observed that a Berkefeld filtrate of the ricinoleated vaccine was without immunizing value in 10 monkeys in the doses employed. The supernatant fluid obtained by centrifuging the vaccine was more antigenic in the immunization of 8 additional animals but not perhaps quite as antigenic as the regular vaccine employed in the immunization of 8 animals. Best results were observed, therefore, with a ricinoleated vaccine of very finely divided cord substance. Of a total of 183 monkeys given subcutaneous and intracutaneous injections of ricinoleated vaccine, 3 or 1.1 per cent developed paralysis during the period of immunization. All of these developed among the 124 animals immunized by subcutaneous injections and occurred during the past year when our strain of virus was of greater virulence than in 1934. None of 59 animals given intracutaneous injections developed any evidences of infection during immunization. The intracutaneous administration of the vaccine, therefore, is apparently safer than subcutaneous injections. All of a group of 18 animals showed the presence of virus neutralizing antibody following subcutaneous and intracutaneous injections of ricinoleated vaccine. All were found protected when inoculated intracerebrally with 0.2 cc. of 5 per cent virus, but when reinoculated 18 days later with 0.5 cc. of 5 per cent virus 3 developed paralysis. We believe that the antibody engendered by ricinoleated vaccine plays some rôle in the immunity of monkeys, but the immunity is relative and probably requires large amounts of antibody for the protection of the nervous system following intracerebral and intranasal inoculations with virus.