Questions on the common cold virus

Flying Penguin

1) How long can this virus last between hosts?
2) When you "get better", what is actually happening? has your body overcome the virus's replicating abilities? evicted it? "killed" it?
3) Can the same virus re-infect one right away? like, say you've just had a cold, gotten better, and then you touch an infected tissue-box or door-handle or something and re-introduce the very same virus to your body - will your body recognise it at all? And sort of related to 1), what if you re-introduce the same virus after some time has passed? which leads us to;
4) why does the body not seem to build immunity to the cold virus? Is it because of small variations in the virus's make-up? (as in, it evolves little changes just enough to stay ahead?)

Thanks in advance

FP - currently enduring his first case of sniffles in some years

Gonzolo

1) I do not know.
2) When you get better, your body has created sufficient antibodies to control the virus population. New virus' can be destroyed before they reproduce.
3) As long as you keep producing the antibodies that got rid of the virus the first time, you'll be looking good.
4) Virus have a complexe structure. A small variation can fool your antibodies. I figure millions of variations or more are possible. Until your body has met them all You can get get a cold. You self-answered correctly. A healthy person will figure out and control a new virus more quickly, possibly to a point where you don't realize you caught it.