Decreased Radiation Mortality in Dogs treated with Typhoid–Paratyphoid Vaccine

Abstract

BACTERIAL endotoxins and bacterial vaccines have been shown to decrease X-radiation mortality in small laboratory rodents^1–4. Typhoid–paratyphoid vaccine (TAB), for example, protects maximally if injected 24 h before irradiation, but, in the mid-lethal dose range, even post-irradiation injection significantly increases survival^2,4. No such protection of bacterial endotoxins or vaccines, administered pre- or post-irradiation, has been reported for large animals. Byron et al.⁵ evaluated the effect of post-irradiation treatment with TAB and antibiotics on survival of irradiated rhesus monkeys. A combination of TAB and antibiotic therapy resulted in no greater survival than was observed with antibiotics alone, so no protective effect was ascribed to TAB. The TAB did, however, affect the haematopoietic system; there was a delayed fall and earlier recovery in numbers of platelets and granulocytes. On the other hand, several years ago, Cronkite and Brecher⁶ reported that survival was significantly increased and granulocyte recovery occurred earlier in dogs in which an abscess had been produced by a post-irradiation injection of sterile turpentine, bacterial cells, and bacterial components of this mixture.