http://en.wikipedia.org/wiki/1918_flu_pandemic
This virus has been around already. Which leads me to wonder, is THAT why fewer elderly people are getting sick from H1N1? Because they and their parents have already been exposed to it? Has the immunity to it diminished over generations?
And based on the assumption that immunity is passed down through generations, wouldn’t our immune systems today have some ability to recognize the virus and fight it? Why is everyone saying our bodies have ZERO immunity to swine flu when H1N1 has been around before?
older people that have been exposed to many flu strains have somewhat more immunity that younger people and kids. the flu is constantly mutating. the seasonal flu shot is only good for the 2 or 3 flu strains that are prevalent. you are never 100% protected against any given flu strain. it,s always a percentage based on each persons’ immunity factor. the flu shots also take a while to work, as the body has to react to the killed virus, and build an immunity to it.
Viruses mutate, oftentimes rapidly. That’s why a seasonal flu vaccine, made months in advance of the flu season often doesn’t immunize against strains that arise due to mutation DURING flu season.
Immunity is not passed down through generations unless a disease kills the poeple who are not immune or resistant. The people who survive any virus are immune to that specific virus usually for the rest of their lives. Eveery time you get a cold or flu it is a new flu to you.
The 2009 H1N1 is not the same as the Spanish Flu, and no two flus are identical. Flus mutate all the time.