Exploring the development of a promising mucosal adjuvant vaccine for human respiratory syncytial virus (RSV) infection

Human respiratory syncytial virus (RSV) is one of the common causes of respiratory illnesses and hospitalizations among infants and young children worldwide, yet an effective vaccine remains unavailable. Cytokines that can activate B-cells and stimulate antibody production, such as thymic stromal lymphopoietin (TSLP), could be used to produce robust and long-lasting mucosal responses to respiratory virus infection. TSLP cytokine is expressed by many immune and non-immune cells, for example airway epithelial cells and mediates a crucial role in activating and maturing dendritic cells and T helper 2 cells. TSLP also promotes cytokine production from activated Th2 cells, such as IL-5, that enhance antibody class switching recombination to IgA, which can protect against viral respiratory infections at the mucosal surfaces. This review is focused on the effect of TSLP on local B-cell responses and IgA antibody production during respiratory viral infections. We suggest that mucosal vaccines could provide better protection against RSV. A novel RSV mucosal vaccine that uses TSLP as an immunostimulant with the RSV Fusion protein (RSV-F) could enhance the local adaptive immune response, generating extended lasting tissue resident memory cells and block early RSV replication, and increase viral clearance from airways. However, additional investigations are required to determine the challenges and limitations of utilizing TSLP cytokine as an immunostimulant combined with RSV-F as it may lead to excessive Th2 immune responses.