Impact of FLU Vaccination on Nasal Resident Memory Immune Responses and Peripheral Respiratory-tropic Memory Immune Responses

Mucosal sites, such as respiratory mucosa, are the primary entry points entry points for pathogens. However, clinical evaluation of vaccines against respiratory respiratory pathogens is currently based primarily on analysis of systemic, i.e. peripheral antibody and cellular responses. These measurements give little indication of the immune responses in respiratory tissues tissues, even though the latter are essential for protection against infection. Protective immune responses in mucous membranes, including respiratory including respiratory tissues, rely on secretory IgA to neutralize pathogens neutralization of pathogens on the mucosal surface, as well as the development of the development of cellular responses, notably those from T (Trm) and B (Brm) lymphocytes. Preclinical studies and a few human studies have demonstrated that Trm are a crucial element mucosal protection against viral and bacterial infections. In fact it has been shown that resident memory lymphocytes, including Trm, are able to able to reside in nasal, pulmonary, intestinal, genital and skin mucosa and skin after infection.

NCT Number	NCT06824779
Lead Sponsor	Centre Hospitalier Universitaire de Saint Etienne Collaborators: Sanofi Pasteur, a Sanofi Company
Conditions	Volunteers, Flu Vaccine
Enrollment	30 participants
Start Date	2025-12-05
Primary Completion	2025-12-19 (estimated)
Study Completion	2026-03 (estimated)
Updated on ClinicalTrials.gov	2025-12-30