For people new to non-drug treatment options, when you go to a reputable health food/vitamin store you will be overwhelmed with all the legitimate vitamins, herbs, homeopathics, amino acids, etc available.
Most people figure out which products work for them through years of trial and error because our bodies are very unique in what they require to maintain a healthy immune system. Often it's not that certain products kill viruses but the products are supplying nutrients our bodies need to kill viruses.
One thing we can all do right now is eat a healthier diet, stay hydrated, get enough sleep, keep our stress levels down. Those basic actions will go a long way in helping our bodies keep us healthy.