I have been taking Turkey Tail mushroom supplements. It is a very effective immune system booster. I have also started taking Agarikon mushroom supplements because it is an effective antiviral agent. These are almost impossible to find in manufactured form right now. A testament to the benefits.
You probably cannot find agarikon mushrooms in the wild but turkey tail mushrooms grow almost everywhere where there are hardwood trees. These mushrooms can be harvested, cleaned and dried and then made into a medicinal tea.
Do your own research but I highly recommend this natural medicine.
Here is a short youtube video about identification and processing. It’s very easy to make your own immune system booster. I plan on beginning to harvest these because my stock of supplements will only last about 6 months.