Along with a healthy immune system, a good common sense approach is also at play. We are not vaccinated, did not even get a flu shot (and will not) going forward. We are careful where we go. Avoid areas where there are large crowds in relatively small spaces. Take precautions when out in public. Hygiene and natural foods, zinc, vitamin D, and tonic water with quinine. All of these boost the immune system. My 97 year old mother and I have NOT had covid even though almost all of our friends, neighbors and family members have had it. BTW, we stay away from hospitals and medical facilities. Do we miss restaurants and going to church? Not any more. We eat healthy, study the Word of God, pray and enjoy our home. Helps us to save money. Those places have no attraction for us now. Our relationship with God and His Son is much stronger than ever before.