I’ve been on Quercetin and VIT C x2/day, 50mg zinc AM and 4000 IU Vit D3 for over a year. Covid hit my house....got my kids and dog.....they shrugged it off like it was the cold/flu. Wife and I never had symptoms. We chalk it up to the FLCCC protocol we have been on for a year and a half. It works. We also took ivermectin as soon as the kids tested positive.
We are all pretty much on the same protocol at my house and none of us have gotten Covid (that we know of), but all of us have been exposed a few times. I’m a big believer that it works.