Most people have heard of the Spanish Influenza. It was the name people eventually assigned to a the deadly strain of flu in 1918. Actually it earned that name before it even existed. See in early months in 1918, a flu swept the world. This strain was not deadly, though. It came through, hit the normal targets. Ravaged them with sickness for about three days, then disappeared again, and left them to recover for a couple of weeks. Of course most of the world was caught up in WWI at the time, so very few countries publicized that anyone was getting sick. Spain, however, was nuetral and its airways were unencumbered by political censorship of that kind. It began to get around that Spain was full of the flu - and before the deadly strain even hit, Spain had been saddled with the "Spanish Influenza."
No one thought much of it until later that year. The deadly virus seemed to spring out of nowhere, and spread rapidly. It attacked the young and healthy instead of the old, or the ones with weaker immune systems. And it was a killer. The effects on the body were pretty horrific. Doctors were shocked by hospitals lined with dying men and women, drowning to death in their own bodies. Hospitals overflowed, whole towns were quarantined.
All in all, the influenza killed more people then WWI, somewhere upwards of 40 million people.
It even inspired a skipping rhyme:
"I had a little bird,
Its name was Enza.
I opened the window,
Scientist tried everything the could to dupicate the virus in hopes of finding the cure. They even took to getting "volunteers" from high security prisons (where they could not have come in contact with the virus previously) and using all manners of methods to infect them, including taking spittle or mucus directly from an infected victim and rubbing into their volunteer's eyes and throat.
Nothing worked, and none of the volunteers got sick. Scientists remained baffled.
The virus worked its course, then disappeared without a trace for decades, until Dr. Taubenberger and his team extracted some of the still-in-tact virus from a woman in Alaska who had been buried in permafrost, thus preserving her lungs.
The last I had read, there was nominal progress, but not much luck recreating the virus.
It's good to see these new leaps and strides.
(Due to time constraints and lack of materials on hand, I regret my lack of detail. I'll repost with more detail and references in the next day or so.)