It's a good question. It's a point about which questions have been raised in a number of settings.
There are two aspects. A pandemic influenza is caused by a novel virus. It's not the seasonal viruses, but there's been a dramatic change in the virus itself, so that the regular susceptibility we have on a seasonal basis is greater, because many of us haven't seen the strain before. It's also an international event from the standpoint that not only has this virus emerged, but it's demonstrated that it can be transmitted very efficiently from person to person, just like seasonal flu, and it's spreading globally.
The WHO definition from the past is that, before they would declare a pandemic, it actually had to affect a number of the WHO regions. There are six of them. I think in terms of our pandemic planning, the situation we found ourselves in is that we thought it was going to be emerging from Southeast Asia, where a lot of the new viruses emerge, and that we didn't need to have a plan in place, or that it would be declared a pandemic before we actually saw it here in Canada.
Actually, the reverse was true. Here we were actually having illness before it was even recognized as a new novel strain, because of Canadian tourists going to Mexico. Nova Scotia was a good example, where they had some school kids who, I believe, were down in Mexico on vacation. British Columbia had tourists who were down there. All of a sudden, when we recognized that this new strain had emerged, it was already spreading around Canada, but it was still not called a pandemic from a WHO perspective, because it was just in North America. It wasn't until after it spread into Europe and some of the other WHO regions that the WHO officially declared it a pandemic.
In a way, that underscores the fact that our plan needs to be flexible, and not just totally dependent on the WHO declaring it to be a pandemic before we activate our plan and get going.