Everytime I feel off like a cold is coming I take ivermectin (apple) paste immediately and Quercetin . I also take it monthly just because. I take chlorella and cilantro extract, followed with coconut charcoal for detox/chelation binding/clearance for five days in a row once a month. Never had a resp infection since. Maybe a runny nose for a day or two. My family refuses to take it and they get a cold maybe twice a year. I'm a nurse and push for homeopathic/native American herbs and plants. Zinc and Vitamin C, and D3. Not regular D. D3. Most people are so low in D3.. and it is a vital part of preventing many cancers.