• Vaccine Name: S. flexneri strain Sfl 124
• Target Pathogen: Shigella
• Target Disease: Shigellosis
• Vaccine Ontology ID: VO_0000673
• Type: Live, attenuated vaccine
• Antigen: The antigen for this vaccine is Sfl 124, which is an S. flexneri Y strain. This strain was derived through the strain Sfl 114 (Hartman et al., 1991).
• AroD gene engineering:
  • Type: Gene mutation
  • Description:
  • Detailed Gene Information: Click Here.
• Preparation: This vaccine is derived from S. flexneri strain SFl 114, which was constructed by making the virulent parent strain Sfl1 an aroD mutant. This rendered it dependent on aromatic metabolites not available in mamillian tissues. The tetracycline resistance properties of Sfl 114 were removed, and this resulting vacccine was called SFl 124 (Hartman et al., 1991). The vaccines were prepared in a lactose-phosphate-glutamate medium with dextran 10 added, then lypholized. All vaccines were rehydrated from the lypholized state with distilled water and diluted with phosphate-buffered saline. Each vaccine contained 3 x 10^8 to 5 x 10^8 organisms, and contained approximately 0.05 ml of cell suspension (Hartman et al., 1991).
• Virulence: Homologous protection occurred after the initial infection with the virulent strain (Hartman et al., 1991).

Guinea pig Response

• Host Strain: Hartley
• Vaccination Protocol: Male Hartley guinea pigs were innoculated. Each guinea pig received 0.05 ml of cell suspension in the conjunctival sac of each eye with a dropper. Immunization occurred on days 0,1,14, and 15. Follwing vaccination, guinea pigs were evaluated daily for the development of keroconjunctivitis (Hartman et al., 1991).
• Persistence: Not noted.
• Immune Response: Sera obtained from guinea pigs reacted with IpA proteins and showed no reaction to the pUC19 control (Hartman et al., 1991).
• Side Effects: The only side effect was keroconjunctivitis (Hartman et al., 1991).
• Challenge Protocol: Animals were challenged with the same strain 4, 7, or 13 weeks after infection (Hartman et al., 1991).
• Efficacy: The attack rate following previous infection was less than 20%. Protection was still more than 80% 7 weeks postinfection (Hartman et al., 1991).