Oromucosal immunomodulation as clinical spectrum mitigating factor in SARS-CoV-2 infection.

Mounting evidence supports the importance of mucosal immunity in the immune response to SARS-CoV-2. Active virus replication in the upper respiratory tract for the first days of infection opens a new perspective in immunological strategies to counteract viral pathogenicity. An effective mucosal innate immune response to SARS-CoV-2 paves the way to an also effective adaptive immune response. A strong local immune response seems to be crucial in the initial contention of the virus by the organism and for triggering the production of the necessary neutralizing antibodies in sera and mucosal secretions. However, if the innate immune response fails to overcome the immune evasion mechanisms displayed by the virus, the infection will progress and the lack of an adaptive immune response will take the patient to an overreactive but ineffective innate immune response. To revert this scenario, an immune strategy based on enhancement of immunity in the first days of infection would be theoretically well come. But serious concerns about cytokine response syndrome prevent us to do so. Fortunately, it is possible to enhance immune system response without causing inflammation through immunomodulation. Immunomodulation of local immune response at the oropharyngeal mucosa could hypothetically activate our mucosal immunity, which could send an early an effective warning to the adaptive immune system. There are studies on immunotherapeutic management of upper respiratory tract infections in children that can place us in the right path to design an immune strategy able to mitigate COVID-19 symptoms and reduce clinical progression.