Exploring immune responses to yellow fever vaccination

Description of the Immune Response to Yellow Fever Vaccination

Not applicable Interventional Institut Pasteur · NCT06718127

This study is testing whether yellow fever and typhoid vaccines can boost the immune system's ability to fight off other infections, and it involves collecting blood samples from participants after they get vaccinated.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment38 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorInstitut Pasteur Industry-sponsored
Locations1 site (Paris)
Trial IDNCT06718127 on ClinicalTrials.gov

What this trial studies

This study investigates the immune response generated by yellow fever and typhoid vaccinations, focusing on the concept of innate immune memory or 'trained immunity'. It aims to determine whether live attenuated vaccines can provide non-specific protection against various infections beyond their intended targets. Participants will have blood samples collected to analyze their immune responses following vaccination. The study is conducted in a real-world setting to observe the effects of these vaccines on the immune system.

Who should consider this trial

Good fit: Ideal candidates for this study are individuals aged 18 to 65 who are scheduled to receive yellow fever and typhoid vaccinations.

Not a fit: Patients with contraindications to yellow fever or typhoid vaccinations, or those who have previously been vaccinated against these diseases, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance our understanding of vaccine-induced immunity and lead to improved vaccination strategies that offer broader protection against infections.

How similar studies have performed: While the concept of trained immunity is gaining interest, this specific approach to studying immune responses to yellow fever vaccination is relatively novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age between 18 and 65
* Referred for immunisation against yellow fever and typhoid
* Any person with indication for the following vaccinations :
* Yellow fever
* Typhoïd
* Whose vaccination schedule includes two appointments 7 days apart
* Whose state of health is compatible with a single 51 ml blood sample collection
* Have consented to participate in the Ivory2 study
* Benefiting from a Social Security plan or equivalent

Exclusion Criteria:

* Anyone with a contraindication to yellow fever and/or typhoid vaccination.
* Any person who has been vaccinated against yellow fever and/or typhoid.
* Anyone who has lived in an endemic area (≥ 1 year) and/or has a history of Typhoid.
* Anyone who is unable to attend the visit 1-month after the typhoid vaccine injection.
* Women claiming to be pregnant or breast-feeding
* Anyone unable to give informed consent for participation

Where this trial is running

Paris

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions ImmunizationInfectionsimmunologyVaccine response
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.