This works just as well for the human immune system as well. Having certain diseases makes you more susceptible to others. Case in point, the HIV virus causes AIDS, but generally death is described as "complications due to AIDS", e.g., non-Hodkins Lymphoma causes about 28% of death due to AIDS related complications (http://www.hivandhepatitis.com/recent/2008/082608_a.html).
Also, if you consider gossip as an unavoidable negative trait (i.e., society will never eliminate it, but we all kind of wish we could), then there are direct analogues in biology. Diarrhea, for example, is analogous to gossip in that sense. And it is a major vector for biological infection.
I suspect you could stretch the analogy even further, but my point is that biological systems have some pretty complex interactions as well.
Also, if you consider gossip as an unavoidable negative trait (i.e., society will never eliminate it, but we all kind of wish we could), then there are direct analogues in biology. Diarrhea, for example, is analogous to gossip in that sense. And it is a major vector for biological infection.
I suspect you could stretch the analogy even further, but my point is that biological systems have some pretty complex interactions as well.