The Role of Mucosal Immunity in the Control of Respiratory Infectious Diseases

Respiratory infectious pathogens such as influenza, respiratory syncytial virus (RSV), and SARS-CoV-2 persist as significant threats to global health. Most of the pathogens come in through the respiratory mucosa, with the local immune mechanisms as the first line of defense. Here, we explore the role of mucosal immunity, such as secretory immunoglobulin A (sIgA), tissue-resident memory T cells (TRM), and inducible bronchus-associated lymphoid tissue (iBALT), in the management of respiratory infections in this research. The mechanistic part illustrates how mucosal vaccination achieves these reactions by protecting within the zone of pathogen entry. There is now experimental data on live attenuated influenza vaccination (LAIV), studies on preclinical SARS-CoV-2 mucosal vaccine, and early human trials that demonstrate the possible role of mucosal vaccination in limiting viral replication and transmission. But the translational challenge is still with various aspects, such as uniform mucosal immune correlates, heterogeneity in formulation and delivery, and regulatory obstacles. Mucosal vaccines provide a compelling complement to systemic immunization but remain challenging to implement. By acting via both systemic and local immunity, these vaccines are likely to play a role in comprehensive respiratory disease control as well as preparing populations for pandemics. These results highlight the necessity for mucosal immunity to be considered as a pillar of future vaccine development and public health policy framework.