According to this article, properties of colloidal silver has been studied.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3993170/

If 30 % of the population get infected and 90 % of infected people recover, whatever they take, then 97 % of the population will be fine, it is much more efficient than any medicine for sale today. But is also very sad for the 3 % that may die.