Products
Typhoid vaccine is commercially available in many countries in the form of enteric-coated capsules (Vivotif) and has been licensed since 1980. The capsules must be stored in a refrigerator between 2-8°C. Injectable Vi polysaccharide typhoid vaccine (Typhim Vi) and Vivotif L, a liquid preparation of Vivotif, are not available in many countries but can be imported from abroad by a pharmacy, subject to regulations.
Structure and properties
The drug contains attenuated live bacteria of strain Ty21a. This strain was obtained by several mutations and is characterized, among other things, by its inadequate ability to form lipopolysaccharides (LPS).
Effects
Typhoid vaccine (ATC J07AP01) stimulates local immune responses in the gut and mediates humoral and cellular immunity. Protection begins 10-14 days after the last dose and lasts at least 1 year. Repeat doses are recommended after 3 years if the patient is permanently living in a risk area (e.g. India), otherwise after 1 year. Efficacy is about 53-78%, according to WHO.
Indications
For oral, active immunization against typhoid fever (typhus abdominalis). The vaccine can be used in children after the fifth birthday. Vaccination should ideally occur 2-3 weeks before travel to a high-risk area. The liquid preparation Vivotif L is approved for use in children as young as 2 years of age.
Dosage
According to the drug label. The capsules are taken with water at least 1 hour before meals on days 1, 3, and 5. The water should not be too hot and should not exceed body temperature (37°C). If swallowing is difficult, the unopened capsule can be administered with a spoonful of yogurt (information provided by the company).
Contraindications
Typhoid vaccination is contraindicated in hypersensitivity, acute febrile illness, immunodeficiency, and concomitant administration of immunosuppressants such as glucocorticoids. For complete precautions, see the drug label.
Interactions
Antibiotics may weaken the effect of the vaccine because they kill bacteria. Malaria prophylaxis should not be started for at least 3 days and should not be given concurrently.
Adverse effects
The vaccine is considered well tolerated. Possible adverse effects include typhoid-like symptoms such as abdominal pain, nausea, diarrhea, vomiting, fever, headache, and rash. Other possible side effects include fatigue, malaise, chills, dizziness, tingling, muscle and joint pain, and allergic reactions.
