Chrome typhoid vaccine

Abstract

1. Experimental typhoid vaccines, treated by 1% formalin and 0·02% chrome alum (KCr(SO4)2.12H2O), as suggested by Japanese workers were prepared and tested by the usual in vitro and in vivo tests.2. Agglutination tests, antibody production in rabbits, active and passive mouse protection tests confirm the stability of the Vi antigen of the vaccine, if properly stored, and the good protection afforded to laboratory animals in both the active and passive mouse protection tests.3. It is suggested that only a full-scale field trial in a typhoid endemic area can give the answer as to the real efficacy and/or superiority of the chrome vaccine over other typhoid vaccines.