Safety and Antigenicity of Typhoid-Shigella sonnei Vaccine (Strain 5076-1C)

Abstract

The form-l antigen of Shigella sonnei was transferred to the avirulent Shigella typhi strain 21a and the resulting 5076-1C transconjugate strain was tested for safety and immunogenicity as a candidate oral vaccine. The transconjugant strain was shown to be well tolerated and safe in 19 human volunteers who were fed from 1 × 10⁷ to 1 × 10¹⁰ organisms. Only two of 10 volunteers tested had developed a rise in antibody titer to the lipopolysaccharide of the hybrid 5076-1C strain.