Bio security at Melbourne Spring Carnival

I have been watching the spring racing carnival on TV over the last few weeks and have noticed the wall that keeps the crowd away from the horses. Why do they even bother with it when a TV host lent over it to speak to a trainer and was centimetres away from his face with a microphone . I think the wall needs to be alot further away because EI is so contagious.
Victoria is sure to get it sooner or later if they don't have it already.

MB (purple zone) Hunter