Active — Not RecruitingPhase 1

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

United States80 participantsStarted 2025-06-12

Plain-language summary

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.

Who can participate

Age range18 Years – 49 Years

SexALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

✓. 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.

Exclusion 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).

What they're measuring

Number and Percentage of participants experiencing any adverse events of special interest (AESI)

Timeframe: Through 90 days after second vaccination

Number and Percentage of participants experiencing any medically attended adverse events (MAAE)

Timeframe: Through 6 months following the second dose

Number and Percentage of participants experiencing any non-serious unsolicited adverse events (AEs)

Timeframe: Through 28 days following each dose

Number and Percentage of participants experiencing any serious adverse events (SAE)

Timeframe: Through 6 months following the second dose

Number and Percentage of participants experiencing new-onset chronic medical conditions (NOCMC)

Timeframe: Through 6 months following the second dose

Number and Percentage of participants experiencing solicited local reactogenicity adverse events (AEs)

Timeframe: Through 7 days following each dose

Number and Percentage of participants experiencing solicited systemic reactogenicity adverse events (AEs)

Timeframe: Through 7 days following each dose

Trial details

NCT IDNCT07019883

SponsorNational Institute of Allergy and Infectious Diseases (NIAID)

Sponsor typeNIH

Study typeINTERVENTIONAL

Primary completion2026-05-15

View on ClinicalTrials.gov More Avian Influenza trials

Plain-language summary

Who can participate

Age range18 Years – 49 Years

SexALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

✓. 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.

Exclusion 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).

What they're measuring

Number and Percentage of participants experiencing any adverse events of special interest (AESI)

Timeframe: Through 90 days after second vaccination

Number and Percentage of participants experiencing any medically attended adverse events (MAAE)

Timeframe: Through 6 months following the second dose

Number and Percentage of participants experiencing any non-serious unsolicited adverse events (AEs)

Timeframe: Through 28 days following each dose

Number and Percentage of participants experiencing any serious adverse events (SAE)

Timeframe: Through 6 months following the second dose

Number and Percentage of participants experiencing new-onset chronic medical conditions (NOCMC)

Timeframe: Through 6 months following the second dose

Number and Percentage of participants experiencing solicited local reactogenicity adverse events (AEs)

Timeframe: Through 7 days following each dose

Number and Percentage of participants experiencing solicited systemic reactogenicity adverse events (AEs)

Timeframe: Through 7 days following each dose