PREPARATION OF TYPHOID SOMATIC-ANTIGEN VACCINE: I. BIOLOGICAL STUDIES OF SALMONELLA TYPHI LYSATES

Abstract

Biological studies of suspensions of S. typhi, lysed with the enzyme dornase, have shown that dornase alters their immunogenic capacity to some extent. However, when prior treatment of the bacterial suspension by sonic oscillation hastened the breakdown process, dornase did not impair the protective ability of the typhoid vaccine, although it eliminated most of its toxicity. In spite of the differences found in the protective ability and toxicity, all the fractions were active in eliciting pyrogen effect and Shwartzman phenomenon.