What is the recommended vaccine for protection against typhoid fever?

Recommended Vaccines for Typhoid Fever Protection

For protection against typhoid fever, either the oral live-attenuated Ty21a vaccine or the injectable Vi polysaccharide vaccine is recommended, with selection based on patient factors and travel circumstances. 1

Available Typhoid Vaccines

Two main types of typhoid vaccines are currently available in the United States:

1. Oral Live-Attenuated Ty21a Vaccine

   • Administration: Four enteric-coated capsules taken on alternate days
   • Efficacy: Approximately 67% protection 1
   • Duration: Protection persists for up to 5 years
   • Age restriction: Not recommended for children under 6 years or immunocompromised persons 1

2. Injectable Vi Polysaccharide Vaccine

   • Administration: Single dose given subcutaneously
   • Efficacy: 51-76% protection 1
   • Duration: Protection lasts approximately 3 years
   • Age: Can be used in children as young as 2 years 1

Selection Algorithm

Choose Oral Ty21a Vaccine When:

• Patient is ≥6 years old
• Patient is immunocompetent
• Patient can reliably follow the 4-dose schedule
• Patient can keep medication refrigerated
• No contraindication to live vaccines exists
• Patient prefers to avoid injections

Choose Vi Polysaccharide Vaccine When:

• Patient is 2-5 years old (Ty21a not approved)
• Patient is immunocompromised (including HIV infection)
• Patient is pregnant (theoretical safety concern with live vaccine)
• Compliance with 4-dose regimen is a concern
• Refrigeration cannot be maintained
• Immediate protection is needed (less than 2 weeks before travel)

Administration Guidelines

Oral Ty21a Vaccine:

• Take one enteric-coated capsule every other day for a total of four capsules
• Take with cool liquid no warmer than 37°C (98.6°F)
• Take approximately 1 hour before meals
• Keep capsules refrigerated
• All four doses must be taken to achieve maximum efficacy 1
• Booster: Repeat entire 4-dose series every 5 years if continued risk 1

Vi Polysaccharide Vaccine:

• Adults and children ≥10 years: 0.5 mL subcutaneously
• Children 2-9 years: 0.25 mL subcutaneously
• Booster: Repeat every 3 years if continued risk 1

Important Considerations

• Efficacy limitations: Neither vaccine provides 100% protection; travelers should still practice careful food and water hygiene 1
• Timing: Vaccination should be completed at least 1-2 weeks before potential exposure
• Adverse reactions:
  • Oral Ty21a: Minimal side effects (<1% report nausea, abdominal cramps, vomiting, rash) 1
  • Vi polysaccharide: Local discomfort at injection site, sometimes with fever, malaise, and headache 1
• Contraindications:
  • Oral Ty21a: Immunocompromised status, children <6 years, concurrent antibiotics
  • Vi polysaccharide: Severe reaction to previous dose

Target Populations

Typhoid vaccination is recommended for:

• Travelers to areas with recognized risk (especially in Asia, Africa, and Latin America)
• Persons with intimate exposure to typhoid carriers
• Laboratory workers who frequently handle S. typhi 1

Vaccination is not routinely recommended for domestic use in the United States, for responding to natural disasters, or for attendance at rural summer camps 1.