A Study to Evaluate the Safety and Immunogenicity of Two Doses of a Novel H5 Central Antigen mRNA-LNP in Healthy Adults

Completed · Phase 1 · Has a placebo group

Conditions studied: Avian Influenza

In brief

This is a phase 1, multicenter, randomized, double-blind trial of two influenza A/H5 mRNA-based vaccines on healthy adult participants, 18-49 years of age. Stage 1 will serve as the open-label, dose finding stage. The first 10 participants will receive 12.5 mcg of H5 AC-Anhui RNA vaccine (Group 1), and the second 10 participants will receive 25 mcg of H5 AC-Anhui RNA vaccine (Group 2). After Protocol Safety Review Team (PSRT) review of reactogenicity and safety data through Day 8 for both Groups 1 and 2, another 10 participants may be enrolled to receive 50 mcg of H5 AC-Anhui RNA vaccine (Group 3). Safety data from 7 days after dose 2 for Groups 1 and 2 participants will be reviewed by the PSRT prior to clearing Group 3 participants for the second dose of vaccine. Individual participants will be followed for approximately 6 months following the second dose of vaccine. The primary objective is to assess the safety of two doses of H5 AC-Anhui RNA vaccine or H5-Astrakhan RNA vaccine administered intramuscularly in healthy adults (18-49 years). Once the Day 36 data from Group 3 are reviewed by the PSRT, a dose will be chosen (12.5 mcg, 25 mcg, or 50 mcg) for advancement to Stage 2 where 50 participants will be randomized 1:1 to receive either H5 AC-Anhui RNA (Group 4) or H5 Astrakhan RNA (Group 5) in a double-blinded manner.

Key facts

Study ID

NCT07019883

Run by

National Institute of Allergy and Infectious Diseases (NIAID)

People needed

80

Starts

2025-06-12

Expected to finish

2026-05-22

Last updated by the study team

2026-06-12

Who can join

Age: 18 and older, up to 49. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• Provides written informed consent prior to the initiation of any trial procedures
• Can understand and agrees to comply with all planned trial procedures and be available for all study visits
• Adult volunteers, age 18-49 years, inclusive, at time of enrollment.
• In good general health.* * Good health is defined by the absence of a medical condition described in the exclusion criteria. If the participant has another current, ongoing medical condition, the condition cannot meet any of the following criteria:
• was first diagnosed within 3 months of enrollment with a clinically significant condition, in the opinion of investigator
• had non-elective surgery, clinically significant medical procedure, or hospitalization within 3 months of enrollment;
• received new prescription for systemic medication within 30 days of enrollment, unless the new prescription is in the same class of agent or a transition from generic to/from brand name equivalent; or
• takes medication that may pose a risk to participant's safety or impede assessment of adverse events or study endpoints if they participate in the study.
• Participants of childbearing potential* must agree to use or have practiced true abstinence** or use at least one acceptable primary form of contraception.*** *These criteria apply to females who are in a heterosexual relationship who are of childbearing potential. Participants not of childbearing potential include post-menopausal females (defined as having a history of amenorrhea for at least one year) or a documented status as being surgically sterile (hysterectomy, bilateral oophorectomy, tubal ligation/salpingectomy, or permanently implanted contraceptive device placement).
• *True abstinence is complete lack of penile-vaginal intercourse. Periodic abstinence [e.g., calendar, ovulation, symptothermal, post-ovulation methods] and withdrawal are not acceptable methods.
• **Acceptable forms of primary contraception include monogamous relationship with a vasectomized partner who has been vasectomized for 180 days or more prior to the participant's vaccination; intrauterine devices; birth control pills; and injectable/implantable/insertable/transdermal hormonal birth control products. Participants must have used >/=1 acceptable primary form of contraception for at least 30 days prior to vaccination and agree to continue >/=1 acceptable primary form of contraception through 60 days after last vaccination.
• Must agree to refrain from donating blood or blood products during the first 6 months of the study
• Body mass index (BMI) 18 kg/m\^2 to 35 kg/m\^2, inclusive, and a weight of 130 kg or less at the time of screening

You may not qualify if…

• Positive pregnancy test at screening or prior to vaccine dose
• Participant who is lactating
• Presence of a significant psychiatric condition that, in the opinion of the site Principal Investigator (PI) or appropriate sub-investigator, precludes study participation
• History of drug abuse or alcohol abuse within 6 months of enrollment that, in the opinion of the site PI or appropriate sub-investigator, precludes study participation
• Has a significant acute illness (with or without fever), as determined by the site PI or appropriate sub-investigator, within 72 hours prior to dosing* *If the participant meets all other eligibility criteria, they may be enrolled and dosed once they meet this eligibility criterion. If the illness resolves within the 28-day screening window, they do not need to be rescreened, otherwise they will need to be rescreened
• Currently enrolled in or plans to participate in another clinical trial with an investigational agent
• Has a history of anaphylaxis to any drug compound, vaccine, food, or other substance, unless approved by the Investigator (or designee)**
• *Sensitivity to components of the study product is exclusionary.
• Received any live-attenuated or mRNA vaccine in the 28 days prior or any other vaccine in the 14 days prior to study vaccination
• Has used any prohibited medication within 30 days prior to Day 1 or plans to use prohibited medications*** through Day 57
• **Prohibited medications include systemic immunosuppressive drugs, immune modulators (except acetaminophen or non-steroidal anti-inflammatory drugs), oral corticosteroids, and systemic antineoplastic agents. Topical, inhaled, and intranasal steroids, as well as topical anti-neoplastic agents are acceptable
• Abnormal blood pressure or temperature (Grade 1 or higher) at time of vaccination
• ***Grade 1 or higher is equivalent to: Systolic blood pressure (SBP) > 140 mmHg or < 90 mmHg Diastolic blood pressure (DBP) > 90 mmHg Oral temperature >/= 38.0 degrees Celsius (100.4 degrees Fahrenheit)
• Abnormal heart rate (Grade 2 or higher) at time of vaccination
• Known and current human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV) infection, based on medical history
• Extended exposure (e.g., occupational or home exposure) to cattle or poultry since March 1, 2024
• Ingestion of non-pasteurized milk since March 1, 2024, or plans to drink non-pasteurized milk during participation in the trial
• Prior receipt of an influenza A/H5 vaccine
• History of myocarditis or pericarditis
• Has any medical disease or condition***** that, in the opinion of the site PI or appropriate sub-investigator, precludes study participation****** *****Medical conditions include, but are not limited to, kidney disease with creatinine clearance < 89 mL/min/1.73 cm2 Chronic Kidney Disease Epidemiology Collaboration method (CKD-EPI); known active liver disease; ischemic heart disease, clinically significant cardiac conduction disorder, arrythmia requiring treatment, congenital long QT syndrome, uncompensated heart failure; diabetes requiring insulin; neuropathy or myopathy; history of Guillain-Barré Syndrome; and malignancy (not including squamous cell skin cancer, basal cell skin cancer, or cervical lowgrade squamous intraepithelial lesions) ******Participation may be precluded due to safety concern or inability to adequately evaluate clinical trial endpoints.

Where it is running

• Duke Vaccine and Trials Unit — Durham, North Carolina, United States
• Vanderbilt University Medical Center — Nashville, Tennessee, United States
• Baylor College of Medicine — Houston, Texas, United States

Full record on ClinicalTrials.gov

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