• Vaccine Name: Vivotif
• Target Pathogen: Salmonella spp.
• Target Disease: Salmonellosis
• Product Name: Typhoid Vaccine Live Oral Ty21a
• Tradename: Vivotif
• Manufacturer: Berna Biotech, Ltd
• Vaccine Ontology ID: VO_0000120
• CDC CVX code: 25
• Type: Live, attenuated vaccine
• Status: Licensed
• Location Licensed: USA (License # 1632)
• Host Species for Licensed Use: Human
• Antigen: The antigen is live, attenuated strain Ty21a (Levine et al., 2007).
  
  
  
• Preparation: Ty21a in enteric-coated capsules was created with 2 × 10^9–5 × 10^9 cfu of Ty21 (Levine et al., 2007).
• Immunization Route: Oral
• Storage: between 2 °C and 8 °C (35.6 °F– 46.4 °F).
• Approved Age for Licensed Use: 6 years of age and older.
• Contraindication: Hypersensitivity to any component of the vaccine or the enteric-coated capsule (FDA: Vivotif).
• Description: Indication: VIVOTIF is used for immunization of adults and children greater than 6 years of age against disease caused by Salmonella typhi (FDA: Vivotif).

Human Response

• Vaccination Protocol: Two trials were completed with Ty21a: In the first, Participants were randomly allocated to receive, 1 week apart, either 2 doses of Ty21a in enteric-coated capsules, 1 dose of Ty21a and 1 dose of placebo, or 2 doses of placebo. In the second, participants were randomly allocated to receive 3 doses of vaccine in 1 of 2 different formulations or placebo. One formulation of Ty21a was enteric-coated capsules, and the other was a triad of gelatin capsules, with 1 containing lyophilized vaccine and the other 2 containing NaHCO3 buffer.
• Persistence: Not noted.
• Immune Response: Doses of Ty21a in capsules stimulates a form of antibody-dependent cellular cytotoxicity, in which IgA antibodies provide the specificity for cells to kill Salmonella organisms. Ty21a stimulates strong classical cell-mediated immune responses involving specific T cells that are believed to function through different effector mechanisms, such as production of IFN-gamma and other cytokines when stimulated by inactivated whole bacilli and purified S. Typhi flagella and the appearance of cytotoxic T cells that kill target cells infected with S. Typhi (Levine et al., 2007). Unless a complete immunization schedule is followed, an optimum immune response may not be achieved (FDA: Vivotif).
• Side Effects: The most common side effects reported were: abdominal pain, nausea, headache, fever, diarrhea, vomiting and skin rash (FDA: Vivotif).
• Efficacy: Results from clinical studies indicate that adults and children greater than 6 years of age may be protected against typhoid fever following the oral ingestion of 4 doses of VIVOTIF (FDA: Vivotif).