Study of Immune Responses to Seasonal Influenza Vaccination in Healthy Adults Exploring How Birth Year Affects Vaccine Response

What this Trial Is About

Researchers are studying how the immune system responds to seasonal influenza vaccination in healthy adults of different birth years. The study aims to understand how early life exposure to influenza viruses influences antibody and cellular immune responses later in life. This investigation focuses on the differences in immune responses caused by the initial influenza virus someone was exposed to, which may affect vaccine response and effectiveness. Participants will receive a seasonal, inactivated, quadrivalent influenza vaccine administered intramuscularly at a dose of 15 micrograms of hemagglutinin HA per component, as approved by the FDA. Up to 100 participants will be enrolled each year to capture a range of birth years. The study will observe immune responses before and after vaccination over a period of up to seven years. During the study, participants will have their blood samples collected to measure both cellular and humoral immune responses to the vaccine. Researchers will evaluate neutralizing antibody levels as the primary outcome, along with secondary measures such as serum antibody changes, levels of specific antibodies binding to viral components, and T follicular helper cell responses. Participants will be monitored throughout the study duration to assess these immune responses and ensure safety.

Characterization of Humoral and Cellular Immune Responses Elicited by Influenza Vaccination in Healthy Adults