Updated Recommendations for the Use of Typhoid Vaccine — Advisory Committee on Immunization Practices, United States, 2015

Brendan R. Jackson, MD; Shahed Iqbal, PhD; Barbara Mahon, MD


Morbidity and Mortality Weekly Report. 2015;64(11):305-308. 

In This Article

Vaccine Administration

Vi Polysaccharide

Primary vaccination with Vi polysaccharide consists of one 0.5-mL (25-μg) dose administered intramuscularly. This vaccine should be given at least 2 weeks before potential exposure.


Primary vaccination with live-attenuated Ty21a vaccine consists of one enteric-coated capsule taken on alternate days (day 0, 2, 4, and 6), for a total of four capsules. The capsules must be kept refrigerated (not frozen). Each capsule should be taken with cool water no warmer than 98.6°F (37.0°C), approximately 1 hour before a meal. All doses should be completed at least 1 week before potential exposure.

Repeat Doses

If continued or repeated exposure to Salmonella serotype Typhi is expected, repeat doses of typhoid vaccine are needed to maintain immunity (Table). An optimal revaccination schedule for the Vi polysaccharide vaccine has not been established; however, the manufacturer recommends a repeat dose every 2 years after the primary dose if continued or renewed exposure is expected.[20] The manufacturer of Ty21a recommends revaccination with the entire 4-dose series every 5 years if continued or renewed exposure to Salmonella serotype Typhi is expected.[21]