We on this island are very lucky with regards to viruses with the channel as the buffer.It is a credit to the fanciers on the Continent that they manage to keep flying at all with their borders all attached to each other the spread of the virus can go from place to place within days maybe even hours so to be able to combat these things they have to be on the ball and maybe that's why the Government agencies act so quickly without all the knee jerk actions - only an observation but would you allow your birds to catch pox,para,salmonella no, in most cases we vaccinate or treat and what do we say how are birds to develop an immunity if they are never exposed. Think about kids measles,chickenpox vaccinate then what do we do send them to play with the "infected" to develop an immunity. May be wrong but prove it