ABSTRACT
The rapid emergence and global dissemination of SARS-CoV-2 that causes COVID-19 continues to cause an unprecedented global health burden resulting in more than 4 million deaths in the 20 months since the virus was discovered. While multiple vaccine countermeasures have been approved for emergency use, additional treatments are still needed due to sluggish vaccine rollout and vaccine hesitancy. Immunoadjuvant compounds delivered intranasally can guide non-specific innate immune responses during the critical early stages of viral replication, reducing morbidity and mortality. N-dihydrogalactochitosan (GC) is a novel mucoadhesive immunostimulatory polymer of β-0-4-linked N-acetylglucosamine that is solubilized by the conjugation of galactose glycans. We tested GC as a potential countermeasure for COVID-19. GC administered intranasally before and after SARS-CoV-2 exposure diminished morbidity and mortality in humanized ACE2 receptor expressing mice by up to 75% and reduced infectious virus levels in the upper airway and lungs. Our findings demonstrate a new application for soluble immunoadjuvants like GC for preventing severe disease associated with SARS-CoV-2.
Single Sentence Summary The immunoadjuvant N-dihydrogalactochitosan diminishes SARS-CoV-2 disease in humanized ACE2 mice representing a new countermeasure against COVID-19.
Competing Interest Statement
TH and SSKL declare a conflict of interest as employees with minority ownership stakes of Immunophotonics, Inc., the manufacturer of the proprietary immune stimulant GC. RML declares a conflict of interest as an advisor with minority ownership stake in Immunophotonics.
