I spent almost a year living and working on the property of Utopia Silver owner Ben Taylor - and much of that time was spent working in a office directly above his manufacturing facility for his outstanding colloidal silver. That stuff wipes out just about everything under the sun EXCEPT one thing: Ben, myself and his other workers all came down with persistent upper respiratory congestions and coughs on more than one occasion and it ALWAYS happened after heavy chemtrail activity. Whatever those things are, they are evil!
The colloidal silver did help quite a bit, but it could not knock it out like it could most other things. What helped me and the others the most was the Clear Lungs, product mentioned in a post below. Using it, along with colloidal silver and echinacea would beat the congestion and coughing within a matter of days every time. I took copious amounts of the silver (two to four ounces a day) and echinacea (triple the normal amount) and the recommended dosage for Clear Lungs. Since your problem has been persistent, you might wish to opt for the extra strength version.
For concerns about the avian and other influenzas I recommend you take a look at this entry in the Remedies section of my website, which I researched and wrote: