Egg-based H5N8 influenza vaccine at multiple doses with or without adjuvant in healthy adults

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This early-phase study evaluates the safety and immune response of an egg-based H5N8 influenza vaccine across three dose levels (low, medium, high) with or without the Matrix-M adjuvant. Healthy adults receive two injections in the arm and are followed for up to about 14 months. The trial helps determine if the adjuvant increases vaccine immunogenicity and whether higher doses provide better immune responses with acceptable safety. Enrollment targets healthy volunteers, and key exclusions include immune compromise, certain infections, and a history of Guillain-Barré syndrome or related neurologic conditions.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Aged 18 years or above on the day of inclusion
* Participants who are healthy as determined by medical evaluation including medical history
* Not pregnant/breastfeeding; non-childbearing potential or uses effective contraception/abstinence from ≥4 weeks before the first study intervention dose to ≥8 weeks after the last dose
* Informed consent form has been signed and dated
* Able to attend all scheduled visits and to comply with all study procedures
* Covered by health insurance, if required by local regulations

Exclusion Criteria:

* Known or suspected immunodeficiency; immunosuppressive therapy in past 6 months; or long-term systemic corticosteroid (eg, prednisone for more than 2 weeks in the past 3 months)
* Known hepatitis B or hepatitis C infection (based on medical history)
* Known personal or family history of previous episodes of Guillan-Barré syndrome (GBS), neuritis (including Bell's palsy), convulsions, encephalitis, transverse myelitis, and vasculitis
* Known systemic hypersensitivity to any of the study intervention components or history of life-threatening reaction to the study interventions or products with same substances
* Self-reported thrombocytopenia contraindicating intramuscular (IM) injection based on investigator's judgment
* Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating IM injection based on investigator's judgment
* Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion
* History of A/H5 infection prior to the study participation
* Moderate or severe acute illness/infection (per investigator judgment)/fever (≥ 38.0°C \[≥ 100.4°F\]) on study intervention day. Include participant only after the condition or fever has resolved
* Alcohol, prescription drug, or substance abuse that, in the opinion of the investigator, might interfere with the study conduct or completion
* Any vaccine given 4 weeks before first study intervention or any planned vaccination to be given prior to Day 43 (ie, approximately 21 days after the second study intervention)
* Previous vaccination against A(H5) with an investigational or marketed vaccine. This includes, but is not limited to, influenza subtypes A(H5N1), A(H5N8), and A(H5N6)
* Has received a blood transfusion or blood-derived products, including immunoglobulins in the past 3 months
* Participation in another clinical study for a vaccine, drug, medical device, or medical procedure within 4 weeks before enrollment or planned participation during the present study period
* Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
* Is an investigator, investigator/study center employee, or immediate family member (parent, spouse, natural/adopted child) of the investigator/employee with direct involvement in the study
* Any screening safety laboratory parameters out of normal ranges and assessed as \> Grade 2

The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.

Where it's running

• AMR Clinical Phoenix, Arizona- Site Number : 8400004
  Tempe, Arizona, United States Recruiting
• Peninsula Research Associates- Site Number : 8400011
  Rolling Hills Estates, California, United States Recruiting
• California Research Foundation- Site Number : 8400007
  San Diego, California, United States Recruiting
• Alliance for Multispeciality Research - Coral Gables- Site Number : 8400003
  Coral Gables, Florida, United States Recruiting
• Accel Research Sites Network - DeLand Clinical Research Unit- Site Number : 8400017
  DeLand, Florida, United States Recruiting
• Alliance for Multispeciality Research - Fort Myers- Site Number : 8400001
  Fort Myers, Florida, United States Recruiting

Study contacts

• Study coordinator: Trial Transparency email recommended (Toll free for US & Canada)
• Email: Contact-US@sanofi.com
• Phone: 800-633-1610

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.