In this review, researchers looked at all the studies talking about intranasal therapy in fighting against SARS-CoV-2. They concluded, “Based on the literature review, it is encouraging to note that studies reviewed note that using nasal spray with antiviral properties has promising efficiency and safety in the treatment and prophylaxis against SARS-CoV-2…We propose that intranasal administration of antiviral and virucidal therapies decrease the viral activity in the nasal pathway, thus preventing disease transmission, expedite recovery of patients, decrease severity of symptoms, reduce hospitalization, and mortality.”

Go, Camille Celeste, et al., (2021). Intranasal therapy and COVID-19: A comprehensive literature review. Journal of Allergy and Infectious Diseases. 2(1):9-16