"PROCESS FOR PRODUCING A SUB UNIT VACCINE AGAINST SALMONELLA F EVERS AND THE VACCINE SO PRODUCED" The present invention relates to a process for producing and purification of a sub unit vaccine against Salmonella fevers, typhoid and paratyphoid fevers. The process comprises: fermentation of a highly virulent strain of Salmonella in a semi-synthetic medium at a temperature between 36°C and 37°C, for a period that is a function of the amount of the inoculum separating the bacterial residue from said fermented strain by centrifuging at moderately high speed precipitating the vaccinating Vi-polysaccharide by in the presence of a precipitating solute comprising Cetavlon, at a temperature in the range of 0°C to 4°C decanting by moderately high centrituging for purification and dissolving in pyrogen free water and further precipitating with ethanol decanting by moderately high centrifuging for purification and dissolving in pyrogen free water and further precipitating with cold phenol precipitating the vaccinating Vi-antigen by ethanol, and dissolving the precipitate in physiological saline.
