Well taking a lesson from seasonal flu for example, I mean a pandemic could be radically different but in terms of what we see from seasonal flu we hypothesise that the civil aviation transport, so this is people getting on planes and travelling around the world, are the primary vectors by which the virus is moving from country to country. Now we wouldn't suspect for a pandemic to be any different and so it's likely, in terms of what we've seen over the past few days of people travelling to and from Mexico and moving the virus to different places, that this is certainly one of the mechanisms by which the virus can move around the world.
Dr Colin Russell.
The evolution of flu viruses may remain outside our control, but there are steps we can take to protect ourselves. Brian, where are we in terms of a vaccine?
Well at the moment we don't have a vaccine to this specific virus, the swine element of H1N1, although obviously World Health Organisation and others are actively looking for that. What we're looking at is the extent to which normal seasonal flu vaccine might or might not help. I mean it's not targeted at this virus but actually quite a lot of people will have been exposed to the human H1N1 in their lifetime and there's some reason to believe that the normal seasonal flu vaccine might just boost a little bit of the H1N1 immunity and that might help in this case. It's not certain yet but we're looking into that.