Kathy1,
I followed the link above, as you did, and of course, scientific articles are difficult for the layperson to understand. I found the third article, entitled "Experimental Infection of Chickens as Candidate Sentinels for West Nile Virus" to be very interesting. If you read only the abstract, (the paragraph preceding the actual article) it will be easier to understand.
What I gathered from the article was that chickens are not in much danger from West Nile Virus. Great news! I had wondered about that myself.
It said that none of the chickens in the experiment that were infected with the virus actually developed the disease. Instead, they made antibodies and fought the virus off.
That's what I got out of it, anyway.
Thanks, Jody, for posting that link!