A novel concept for treatment and vaccination against Covid-19 with an inhaled chitosan-coated DNA vaccine encoding a secreted spike protein portion.

A novel concept in DNA vaccine design is the creation of an inhaled DNA plasmid construct containing a portion of the coronavirus spike protein for treatment and vaccination. The secretion of a spike protein portion will function as a competitive antagonist by interfering with the binding of coronavirus to the angiotensin-converting enzyme 2 (ACE2) receptor. The secreted protein binding to the ACE2 receptor provides a unique mechanism of action for treatment to all strains of coronavirus in naïve patients, by blocking the ACE2 receptor site. An inhaled plasmid DNA vaccine replicates the route of lung infection taken by coronavirus with transfected cells secreting spike protein portions to induce immunity. Unlike most DNA vaccines with intracellular antigen presentation through MHC I, the current vaccine relies on the secreted proteins presentation through MHC II as well as MHC I to induce immunity. Lung specific production of vaccine particles by inhaled plasmid DNA is appealing since it may have limited systemic side effects, and may induce both humoral and cytotoxic immunity. Finally, the ease and ability to rapidly produce this plasmid construct makes this an ideal solution for managing the emerging threat of coronavirus.