Being in a high risk category, I got the vaccine early on. I had some flue-like symptoms, but nothing worse. I take vitamin C and D3 as well as zinc daily.
Vitamin C, D3, L-Lysine, probiotics, fish oil, and Quercetin are what I use as Covid prophylactics, along with multivitamins and a few other supplements (e.g., COQ10) for other things.