I use an iota-carrageenan nasal spray that has clinical evidence showing it's effective at reducing the duration of common cold, as well as some protection from

I use an iota-carrageenan nasal spray that has clinical evidence showing it's effective at reducing the duration of common cold, as well as some protection from COVID. Obviously, the COVID research is a bit flimsier. It's also cheap, and carrageenan is pretty inert. I use it any time I'm around big groups of people for more than a few minutes. [1] common cold: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7880062/#:~:text=Therefore%2C%20all%204%20clinical%20trials,absorbed%20from%20the%20nasal%20mucosa https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7880062/#:~:tex.... [2] covid: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8493111/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8493111/