Zinc plays an essential role in the production and proper functioning of white blood cells, but also antibodies. And copper, on the other hand, is going to have a major role, especially in terms of anti-infectives, antioxidant, as well as anti-inflammatory effects, in addition to being essential to fight viruses, but also in case of fatigue and stress.
What you need to know is that a zinc and copper deficiency will inevitably weaken your immune system. And some populations are more deficient, especially the elderly, but also people who are overweight or obese, or even vegans and vegetarians.
These two trace elements, zinc, and copper are mainly found in animal products. They are found in meats, but also in offal, seafood, cheese, and nuts.