Intradermal versus subcutaneous immunization with typhoid vaccine

Area of Science:

• Immunology
• Vaccinology
• Travel Medicine

Background:

• Typhoid fever remains a significant health risk for international travelers.
• Effective immunization strategies are essential for preventing typhoid infection abroad.
• Evaluating different vaccine administration routes is key to optimizing efficacy and safety.

Purpose of the Study:

• To compare the immunogenicity of typhoid vaccine administered intradermally versus subcutaneously.
• To assess the safety and adverse reaction profiles of both administration routes.
• To determine the preferable method for typhoid immunization in travelers.

Main Methods:

• Swedish nationals traveling abroad received a monovalent, heat-inactivated typhoid vaccine.
• Vaccine administration was performed via either intradermal or subcutaneous injection.
• Serum antibody responses were measured using direct agglutination and indirect hemagglutination assays.

Main Results:

• No significant differences in serum antibody responses were observed between the intradermal and subcutaneous groups.
• The intradermal route of administration resulted in fewer reported adverse reactions compared to the subcutaneous route.
• Both vaccination methods demonstrated measurable antibody production against typhoid.

Conclusions:

• Intradermal administration of the typhoid vaccine is a viable and preferable route due to a better safety profile.
• The subcutaneous route is also effective in eliciting an antibody response but is associated with more adverse events.
• This study supports the intradermal route as a preferred method for typhoid immunization in travelers.