H1N1 flu is going around this year, an especially bad flu to which few people under 35 have much immunity. A bad flu year, but not in the same class as the 1918 flu.
The bird flu had potential to be very deadly, potentially as bad as the 1918 flu. The bird flu, an avian influenza A (H5N1) virus strain that emerged in Asia in 2003 had potential to turn into a very deadly human flu. A flu virus emerged that spread as an epidemic in birds or several species. Then it passed to humans–several times–and was very deadly, 60% fatal. While deadly, the virus that humans got was either wouldn’t transmit between people or did so only with great difficulty. Small clusters of people, usually of families that worked or lived with birds, came down with bird flu.
Bird flu needed only one or two mutations to become capable of causing a worldwide pandemic. It needed to pick up the property of easy contagion, human-human transmission. The first steps to contain bird flu in Asia failed. It spread around the world in wild and domestic bird populations and sometimes infected other animals. It has become endemic in bird populations this gives the virus many opportunities to infect humans and pick up mutations to allow it to spread in people.
So far we’ve been lucky, and the H5N1 avian influenza hasn’t turned into a fast spreading human flu epidemic. Perhaps this flu virus is a dead end of sorts and is incapable of jumping to humans. It does keep getting chances and infecting the occasional person so the CDC and WHO continue to monitor it. It has had many chances to become a human epidemic and so far hasn’t, and as time it becomes less likely to jump to humans. It looks like we got lucky.
We didn’t get so lucky with the capacitor plague…