Phase 1 Study to Evaluate Safety and Immune Response of RSV and Flu H5 Vaccines in Healthy Adults Aged 18 to 49

What this Trial Is About

Researchers are evaluating the safety and immune response of different vaccine formulations targeting the Respiratory Syncytial Virus (RSV) monovalent antigen and the Influenza A(H5N1) hemagglutinin subtype 5 (H5) antigen in healthy adults aged 18 to 49 years. This phase 1 study aims to understand how well these vaccines work and how safe they are for this age group, with participation durations varying by treatment group and study stage. Participants receive vaccines through intramuscular injections. For certain groups, injections are given on day 1 and day 22 with the H5 Flu vaccines, while others receive a single injection on day 1 with the RSV vaccines. The study is divided into two stages, with Stage 1 lasting approximately 6 to 7 months depending on the arm, and Stage 2 lasting about 7 months for all arms. Vaccines are given according to a randomization schedule across multiple experimental arms. Throughout the study, participants will be monitored closely for side effects such as injection site reactions, systemic symptoms, and any adverse events up to 6 months after vaccination. Researchers will collect blood samples to measure antibody responses before and after vaccination at various time points. The study includes detailed safety assessments, including biological tests and documentation of any serious adverse events or events leading to discontinuation. Participants' immune responses to both RSV and Flu H5 antigens will be measured using specific antibody tests over the course of the study.

Study of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Participants 18 to 49 Years of Age