Rigorous gov.t campaigns and my own sense of pedantry impel me to point out that the common cold is caused by bacteria, not by virii. That's why antibiotics don't work against it :-)
As for mutation, I've seen a bug go around a circle of friends and have obviously changed by the fourth or fifth infectee.
1. I couldn't find much by way of supporting your "bacteria not virus" idea, and a few sources directly contradicting it. Got a cite?
2. I wonder what the odds are, then, that it was the same virus mutated enough that the immune system of the repeater didn't recognize it vs two viruses making the round(s)...
Ummmmm. . .Catherine, no offense or anything, but my common sense says that your flat wrong. Is this a Bush administration ad campaign?
tossing my two cents in, antibiotics *only* work on bacteria... not viruses.
Yes, antibiotics are only functional against bacteria. Colds are viruses, pneumonia is bacteria. Bacteria reproduce on their own (thus are alive, antibiotic means anti-life), while viruses require a host cell. Taking antibiotics for viral illness encourages the development of antibiotic resitant strains of bacteria.
Also, most cold & flu medications are symptom maskers and do very little to help you get over your cold. (Other than perhaps making it possible to sleep.)
Aaand once again we see the troubles of posting too quickly. Yes, your fine correspondents are all right - antibiotics are only functional against *bacteria*. So I got it the wrong way round - got you all talking, didn't it? ;-)