Can't speak to the differences in effectiveness, bu elderberry extract is sold with zinc already in it to advantage this exact mechanism of action. Also available on Amazon long before covid as an 'immune booster' to fight viruses. So if and when the 'Q' pills are pulled and horse paste regulated, you can turn to that.

And should that meet similar ends, garlic shares the same effect. Almost as if our bodies aren't tailored to work in isolation, but rely on self mediated nutrition from the wild to manage and regulate it's full potential.