"I imagine the U.S. and Canadian governments do have our reports by now but they'll have to watch how the news is released. If they're not careful there could be a panic, with people evacuating the cities and spreading the disease. It takes time to organize police and military units for quarantine guards." "How bad is it likely to be?" she asked. "That's hard to say. The 1918 flu killed twenty million people and attacked about fifty times that number. Since then, ordinary flu epidemics have been reported with up to fifty percent of the people involved. The Asian flu of 1957 affected up to seventy-five percent in some areas. But this stuff isn't pure flu and so there may be absolutely no immunity. Probably the only thing that will prevent people from getting it is not to be near someone else who has it. In the old days that was possible, but with the population we have now, and the rapid communication between towns, it is much easier to spread an epidemic than it was fifty years ago. My guess is that eighty or ninety percent of the population will get it." "John," Pat said thoughtfully, "How long is it likely to be before you start having symptoms?" "You mean all of us, don't you?" I said. "After all, that spray must have splashed a bit and both you and the Chief may have got enough to infect you." "Well, yes, if you put it that way." "Oh, about four days," I guessed, "or, perhaps a day more or less. We aren't quite sure of the incubation period yet, and there's always a chance of a mutation with a shorter period if a synthetic virus is liable. We don't know that either." "It's practically certain you'll be sterile, isn't it?" "I'm afraid so," I said ruefully. "What about convalescent serum, wouldn't it help?" she asked hopefully. "If I got a big enough and strong enough dose, it might. There isn't any ready yet. I asked Hallam just before we left this morning. If it isn't injected early it may modify the disease but probably wouldn't prevent it completely. I might still be sterile. It doesn't always work anyway." "What about me?" "Last night, before I went to bed, Dr. Hallam got a report that very few women had shown symptoms of sex gland involvement. The biopsies taken by Bruce Thompson from the ovaries of women who have had the flu showed only minor changes that Smith could detect. That isn't absolute proof that everything is all right, of course. It will take time to find that out." "What about miscarriages in infected women," she persisted. "They checked that out too. There have been occasional cases, but no more than you are likely to see with any heavy fever. That ferret may have been an exception. Perhaps it's a peculiarity of the ferret's reaction to the virus. It may prove to be a rare complication in people. Of course we don't know yet if the children of infected mothers will be born deformed in any way, as they often are in German measles. This virus may have no such power."