The current projections for potential attack rate, quite frankly, have varied quite a bit. We've done some mathematical modelling. We think that the ultimate attack rate in this wave of the epidemic, population-wise, would be somewhere between 25% and 30%; that is, 25% to 30% of the population will get hit, basically, this fall, assuming that the vaccine isn't out there. That's on the low end of pandemic attack rates, basically. Pandemic attack rates historically have been between 25% and 40%. So you can figure that a good portion of the population is going to be hit.
Now, I think the key question is this: what percentage of those people will become critically ill or ill enough to be in hospital? The numbers and the projections on that, quite frankly, are all over the place. I don't think anybody is really certain. Initially we were talking about one in 250, which is a number that has been used in seasonal influenza. My estimate is that the number has gone down fairly substantially. I suspect that it's on the order of one in 1,000, or less.
Again, we have some data we've recently submitted to the CMAJ. By the way, the data I gave you just a moment ago on the time to antivirals was developed by Ryan Zarychanski, one of my colleagues.
We've developed some data that looked at a dynamic model of the number of cases we might see, assuming that the vaccine was not aggressively deployed. We thought we might see as many as somewhere in the ballpark of 1,500 to 2,500 cases simultaneously across the country. That's more or less a worst-case scenario, because we only have about 3,000 ICU beds--that's a ballpark figure--across the country.