Cell Wall Structures Which May Be Important for Successful Immunization withSalmonella-Shigella Hybrid Vaccines

摘要

Three separate lots of S. typhi/S. sonnei hybrid (Ty/Shig) live oral vaccinestrain 5076-1C were tested for efficacy in human volunteers challenged with virulent S. sonnei. Two lots (2 and 5) protected volunteers, a third lot (8) did not. The 3 lots were evaluated by immunologic tests and electron microscopy. Lots 2 and 5, which protected, contained bacteria that reacted with anti-flagellar serum and has observable attached flagella and pili. Lot 8, which failed to protect, did not react with anti-flagellar serum, and had no observable pili. There was no correlation between vaccine efficacy and the reaction of IgC in patient's sera in western blot analysis. Surface structures on the Ty-Shig hybrid may be important for generating a protective immune response. (JES)