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

Overview

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.

An initial MUCOVAC clinical trial (NCT06469359), sponsored by the CHU of Saint-Etienne and in collaboration with Jean Monnet University (GROUPE ON MUCOSAL IMMUNITY AND PATHOGENS (GIMAP)) has made it possible to set up a methodology for collecting and analysis of nasal resident memory T and B lymphocytes, and to detect peripheral memory lymphocytes that have the capacity to migrate into respiratory tissues. In this randomized cross-over study, the investigators investigators compared three nasal cell harvesting devices in a cohort of a cohort of healthy volunteers: (i) a nylon swab (FlowSwab, Copan Diagnostics), (ii) a plastic curette (Rhino-pro curette, Arlington Scientifc) and (iii) a mini cytological brush (Microm Microtech). This study determined that the nylon swab (data not yet published) is the most to collect viable memory resident lymphocytes from the nasal sphere.