PHYSICAL AND CHEMICAL STUDIES OF TWO DRIED INACTIVATED TYPHOID VACCINES (VACCINES K AND L).

This paper reports on studies of the physical and chemical properties of dried acetone-inactivated and heat-phenol-inactivated typhoid vaccines (vaccines K and L respectively) which have been tested in controlled field trials in British Guiana and Yugoslavia. Determinations of nitrogen, dry weight, moisture and salt contents were made in Washington and Copenhagen. Eight laboratories collaborated in opacity determinations on the reconstituted vaccines.