A. Vogel Echinaforce Drops Echinacea has been used for many years & is extremely beneficial against weak immune function, infection, colds, flu, bronchitis & inflammatory diseases. Echinacea is used extensively for boosting the immune system by stimulating a group of cells that destroy viruses & bacteria. Echinacea is also used by millions as their primary therapy for colds & flu. It works by increasing the production of interferon, an important part of the bodys response to viral infections.