Preparation of protective vaccines Against some Diseases prevalent in A.R.E

1. The research is mainly an attempt to find out a solution for the problem of immunization against typhoid and paratyphoid A fevers, which are among the most ,prevalent infectious diseases in Egypt.2. Acetone chloroform, amyl alcohol, propylenglycol and. benzalkonium chloride were used for the preparation ofinactivated antityphoid and antiparatyphoid A vaccines.3. The protective potency of the prepared vaccines was examined mainly by the active mouse protection test.4. In mice immunized with a single intrraperitoneal dose of the vaccine . (containing 5 x108 cells/mouse) and challenged with 12.5 LD 50’s dose/mouse, the following have been obtaineda- The acetone inactivated vaccine afforded 100%b- The chloroform vaccine 66.7 protectionc- Concerning amyl alcohol vaccine, the Lower layeraffords 80 % protection and the Upper layer affords 100 % protection.d-The propylenglycol ’vaccine 69 % protection.