Type: Salmonella typhi Vi Capsular Polysaccharide Vaccine
Form: Solution for intramuscular injection
Manufacturer: Sanofi Pasteur Limited
Indications and Clinical Use
Indication:
Active immunization against typhoid fever caused by Salmonella typhi.
Recommended for individuals 2 years of age and older, particularly travelers to endemic areas, those with reduced gastric acid secretion, people in close contact with an S. typhi carrier, and laboratory workers handling S. typhi cultures.
Dosage and Administration
Recommended Dose:
Adults and Children (2 years and older): Single 0.5 mL dose intramuscularly.
Revaccination: Every three years for those at continuous or repeated risk.
Administration:
Inspect the solution for particulate matter and discoloration before use.
Shake the pre-filled syringe well and administer intramuscularly, preferably in the deltoid muscle or anterolateral aspect of the mid-thigh.
Contraindications
Hypersensitivity to any component of the vaccine, or a history of severe allergic reaction after previous administration of the vaccine or a vaccine containing similar components.
Warnings and Precautions
General:
Inform recipients of the benefits and risks of immunization.
Review medical history for hypersensitivity reactions to similar vaccines.
Procedures should be in place to manage syncope and anaphylactic reactions.
Special Populations:
Pregnant Women: Limited data; use only if clearly needed after risk-benefit assessment.
Breastfeeding: Unknown if excreted in human milk; use with caution.
Immunocompromised Individuals: May have a reduced immune response; vaccination recommended if possible.
Administration Precautions:
Do not administer intravascularly or into the buttocks.
Administer with caution to individuals with coagulation disorders.
Concomitant Vaccine Administration: Can be administered with other vaccines commonly given to travelers, such as meningococcal, hepatitis A, and yellow fever vaccines. Administer at separate sites using separate syringes.
Immunosuppressive Treatments: May interfere with immune response development.
Storage and Stability
Store at 2°C to 8°C. Do not freeze. Protect from light. Use immediately after reconstitution.
Clinical Trials and Efficacy
Efficacy: Demonstrated approximately 75% protection in clinical trials.
Nepal Trial: 75% efficacy against typhoid fever.
South Africa Trial: 60% to 81% efficacy depending on the comparison group.
Immunogenicity: High seroconversion rates observed in children and adults.
Duration of Protection: Immunity lasts around 3 years post-vaccination.
