Influenza (flu) is a contagious respiratory illness that can lead to serious complications, especially in older adults and individuals with certain medical conditions. While current flu vaccines are available, their effectiveness can vary from year to year. Researchers are studying new approaches, including mRNA-based vaccines, to potentially improve protection against circulating flu strains.
This research study is evaluating investigational mRNA influenza vaccines. The purpose is to assess their safety, tolerability, and how the immune system responds compared to currently approved flu vaccines.
Participants will receive a single injection of either an investigational mRNA flu vaccine (one of several dose formulations) or a licensed influenza vaccine already approved for use (used as a “control” for comparison).