• Vaccine Name: CVD 1208S
• Target Pathogen: Shigella
• Target Disease: Shigellosis
• Vaccine Ontology ID: VO_0000668
• Type: Live, attenuated vaccine
• Antigen: The antigen for this vaccine is CVD 1208s, which is Shigella flexneri containing deletions in sen, set, and guaBA (Kotloff et al., 2007).
• Preparation: The inocula were derived from frozen master cell banks containing prepared strains of CVD 1208S. Frozen master seed was plated onto SP agar. After incubation, several Congo Red-dyed colonies proven to be Shigella were suspended in sterile saline. This saline was used to inoculate SP plates for the heavy bacterial growth. These resulting colonies were harvested into PBS and diluted to the appropriate bacterial count, which was between 1 x 10^8 and 1 x 10^9 CFU per ml (Kotloff et al., 2007).
• Description: CVD 1208S is the same thing as CVD 1208, but CVD 1208S was prepared using animal-free media (Kotloff et al., 2007).

Human Response

• Vaccination Protocol: 16 volunteers were assigned to receive between 1 x 10^8 and 1 x 10^9 CFU per ml of CVD 1208S or a placebo. Volunteers ingested a buffer solution, then ingested 1 ml of vaccine or placebo suspended in 30 ml of buffer solution. Vaccine excretion was monitered through the culture of all stools and through collection of blood samples (Kotloff et al., 2007).
• Persistence: Vaccine was detected in the stool of all volunteers that received the 1 x 10^9 CFU dosage for at least one day. The same was true for six of the volunteers that received 1 x 10^8 CFU, with no vaccine detected in the volunteers that received the placebo. Peak excretion occurred on Day 1 and total excretion did not exceed the dosage levels (Kotloff et al., 2007).
• Immune Response: Following vaccination, all subjects mounted an anti-LPS IgA ASC response and 5 exhibited an anti-LPS IgG ASC response. Anti-LPS responses typically reached a peak on Day 14. Some volunteers exhibited a serum antibody response to Ipa and IpaB. All recipients of the higher dose (1 x 10^9 CFU) demonstrated a response in two or more of the immunologic assays (Kotloff et al., 2007).
• Side Effects: Side effects included mucoid or loose stools and fever, in some cases (Kotloff et al., 2007).