Our son came to visit from L.A. to Naples and then to us in Ohio, before returning to L.A. No shot, but he still got sick 3-4 days after back home. He tested positive for Covid via a home test. I have told him until I am blue in the face: 1) Covid has not been isolated so you probably have the flu or a bad cold, or a flu variant, 2) The PCR tests can not test for Covid vs the flu, vs a cold, 3) At home tests are very inaccurate, worse than the PCR test. He took what I sent him previously, or at least he said he did: quercitin, Vitamin C, Vitamin D, and zinc. Not sure if it helped him or if it just ran its course. I should have thought to tell him to take it the entire time befor, during and after travel. We are in our 70’s and neither of us have been sick. We have vitamin D levels >50, take Vitamin C and D daily, and have other “meds and therapeutics” on hand if needed. I am kicking myself for not sending him back home with the miracle pill from another country, if you catch my drift. You live and learn. I never thought he would get sick, because he seemed to have gotten whatever this is in early 2020. The only thing I can say in our favor is: we cook all food from scratch, only eat out occasionally (not fast food), rare alcohol, no smoking. While he, although slim and in decent shape, is single, hates to cook and orders fast food, rarely eats fruits and veggies (although as a child he ate fruit and vegetables every meal.