WNV

[CMNewell <reshan@deyr.ultranet.com>]

>.....otherwise if by chance you would want to transport to some big ride
>out of the states your horse would test positive and you couldn't prove
>it was the vaccine causing a false positive


Huh? What ride would be testing horses for West Nile virus?  Besides, 
horses with a natural exposure which don't become ill can carry a 
significant titer. (there were a number of these in areas where horses were 
clinically ill).
             --CMNewell, DVM

(Vaccinating for WNV in Massachusetts)