Most public inoculation programs typically begin in October, shortly before the beginning of the cold and flu season. For the 70 to 76 million people estimated to be at high risk for serious flu-related complications, this could be too late. According to multiple clinical studies, herbs and vitamins can significantly strengthen the immune system, helping the body resist infection or shorten the duration of cold or flu symptoms. The findings from a Swedish study showed that daily treatment with Echina Guard, from the first signs of an upper respiratory infection, inhibits the full expression of the disease and also can lead to more rapid recovery than in patients treated with placebo.
Additional studies support the use of echinacea for decreasing duration of cold symptoms.
A series of studies from Israel have shown that in patients with influenza, a complete cure was achieved within two to three days in nearly 90 percent of the Sambucol-treated group and within at least six days in the placebo group. This difference showed a high degree of statistical significance. These lozenges contain zinc gluconate, the form of zinc salt that has been shown to be most effective in minimizing cold symptoms. When taken at the very first sign of a cold, this product can decrease symptoms and shorten duration of colds, as documented in several scientific studies published in major journals. A deficiency of Selenium has been shown to inhibit resistance to microbial and viral infections.