PARTICIPANT: One of the problems with deciding whether there will be another 1918 or not is that there will never be another 1918, because 1918 was a year replete with secondary bacterial pneumonia in many of these victims. We talk about the high mortality in that year. It was also true that 98 percent of the population had ordinary three day fever and flu. In addition, the summer of 1918 was an unusually cold one, in which case there would be more people indoors and the possibility for more abundant transmission and so forth. Another point about another 1918 is again, it is not 1918. We have learned a great deal. We know how to make vaccines. We know what kind of virus is causing this; we have antivirals.
PARTICIPANT: I think these points are really good. The point that I would make to that is that I think we really have to consider in a sense each pandemic as a unique event. And if you have a unique circumstance—when a unique virus emerges that can circulate in humans—that is going to be different from one pandemic to another in terms of what has happened in the past, what kind of other strains have circulated in the past, and what the immunity in the population by different ages would be. So, I think that we should not generalize. It is clear going back to the molecular biology, looking at the genetics of the 1918 virus versus the 1957 or 1968 virus is clearly where we are seeing differences by which pandemics may emerge, and clearly that is a useful model.
Another difficulty, however, is that even just looking at 1918, with all the work that has been done for 80 years on this virus; we are still missing so much of the primary data that we really need to understand what happened. We have no pre-1918 human samples to study. We have no sera collected before 1918; we are never going to have those data. And if we are not going to have data before 1918, it is going to be very, very difficult to go back to what happened in the very distant past. So, we have the epidemiologic evidence that exists, and we can use that data to sort of tease out hypotheses. But the problem is that going back in the past is going to be extremely difficult to develop experimental models.
DR. FINEBERG: It seems that the fundamental problem in one sense is that the time horizon for an observation—a pandemic—goes back centuries to obtain a handful of type of observations. And in our lifetimes, where we are accustomed to looking at organisms that turn over in the hours, rather than units of observation that take decades or centuries to become apparent, we are not accustomed to thinking as cautiously as you are now advising us about generalizing from such a paucity of real observation. And I think that is a pretty important caution. At the same time, the premise of all of our work on thinking of a research strategy has to be that we believe what we learned from the past can help us in the future. And so, being modest about it, and being properly qualified I hope at the same time will not deter us from making the effort that we are all engaged in today. And I know you certainly wouldn't want that to be the case.
PARTICIPANT: I think a very important point was made, and was made very quickly, and that is about the usefulness of having challenge strains available, contemporary challenge strains of virus. Economically, this can be very cost effective to do this, because instead of having to go to complicated and very costly and dangerous clinical trials, it means that you could develop at least attenuated strains of contemporary viruses to have those available. I say this with feeling, because I have recently been through an experience with a clinical trial where an up-to-date strain was not available. So, we came away with the conclusion that we could not affect enough of a control population to come up with any kind of answer. So, I think cost effectively, this would be very important.