An oral vaccine (Ty21a, Vivotif Berna vaccine, Swiss Serum and Vaccine Institute) is available for prevention of typhoid fever. This contains a live-attenuated strain of Salmonella typhi.


Dosing: 4 doses on alternative days (Days 1, 3, 5, and 7)


Booster series: recommended every 5 years


Protective efficacy: variable, ranging from 40 to 96%


Additional instructions: Water and food precautions must be observed since protection is incomplete.


Contraindications to use:

(1) age of the patient < 6 years of age

(2) immunosuppressed

(3) noncompliant with instructions for taking doses or storing doses in a refrigerator


Delay starting the vaccine for at least 24 hours after last dose of the following:

(1) antibiotic therapy

(2) mefloquine

(3) progruanil (may impair production of anti-lipopolysaccharide antibodies)

Do not treat the patient with any of these during the vaccination sequence.


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