VRC 329: A Phase I Open-Label, Clinical Trial to Evaluate the Safety, Tolerability, and Immunogenicity of a Quadrivalent Influenza HA Stem Vaccine VRC-FLUMOS0122-00-VP (STEMos1) With and Without ALFQ Adjuvant in Healthy Adults
Background: Influenza (flu) is a contagious respiratory illness caused by viruses. Flu symptoms can range from mild to severe, and the illness can be fatal. Vaccines help the body learn to prevent or fight infections such as flu. Some vaccines are combined with adjuvants. Adjuvants are special salts or fats that help vaccines work better. Researchers are looking for ways to make flu vaccines more effective.
Objective: To test a new flu vaccine with and without a new adjuvant.
Eligibility: Healthy adults aged 18 to 50. They must have had at least 1 flu vaccine since 2020.
Design: Participants will have 12 clinic visits over 15 months. The vaccine is given as an injection into the muscle of the upper arm. Participants will be vaccinated during 2 visits spaced 4 months apart. Half will receive just the vaccine; half will receive the vaccine plus the adjuvant. They will be monitored for at least 30 minutes after each shot. Participants will keep a diary for 7 days after each shot. They check their temperature every day and record any symptoms. Participants will have 10 follow-up clinic visits plus 4 phone calls. They will have 4 to 10 tablespoons of blood drawn at each clinic visit. Fluid samples will be collected from their nose and mouth. They will be checked for any health changes. Participants may opt to undergo apheresis: Blood will be taken from the body through a needle inserted into a vein. The blood will pass through a machine that separates out the white blood cells. The remaining blood will be returned to the body through a different needle.
⁃ A participant must meet all of the following criteria:
• Healthy adults between the ages of 18-50 years, inclusive
• Based on history and physical examination, be in good general health and without a history of any of the conditions listed in the exclusion criteria
• Received at least one licensed influenza vaccine from the 2020-2021 influenza season through the 2024-2025 influenza season
• Able and willing to complete the informed consent process
• The ability to read and comprehend English as all consent and recruitment materials are in English.
• Available for clinic visits for 68 weeks after the first dose, including through the 2025-2026 influenza season
• Able to provide proof of identity to the satisfaction of the study clinician completing the enrollment process
• Physical examination and laboratory results without clinically significant findings and a Body Mass Index (BMI) \<= 35 within the 56 days before enrollment
• Agrees to not receive any licensed influenza vaccination during study participation due to potential confounding of study results
• Willing to have blood and mucosal samples collected, stored indefinitely, and used for research purposes.
⁃ Laboratory Criteria within 56 days before enrollment:
• WBC and differential within institutional normal range or accompanied by approval of the site Principal Investigator (PI) or designee
• Total lymphocyte count \>= 800 cells/microliter
• Platelets = 125,000-400,000 cells/mircoliter
• Hemoglobin within institutional normal range or accompanied by approval of the PI or designee
• Alanine aminotransferase (ALT) \<= 1.25 x institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST) \<= 1.25 x institutional ULN
• Alkaline phosphatase (ALP) \< 1.1 x institutional ULN
• Total bilirubin within institutional normal range or accompanied by approval of the PI or designee
• Serum creatinine \<= 1.1 x institutional ULN
• Negative for HIV infection by an FDA-approved method of detection
⁃ Criteria applicable to women of childbearing potential:
• Negative beta-human chorionic gonadotropin (beta-HCG) pregnancy test (urine or serum) on the day of enrollment
• Agrees to use an effective means of birth control from at least 21 days prior to enrollment through the end of the study