Black Bullet, an anime which I will absolutely not continue watching, is worth mentioning to muse a bit about the biology of its premise.
Premise: 10 years ago, a parasitic virus nearly wipes out humanity, before people discover a metal called Varanium which kinda functions like kryptonite to the parasites. Since then, some children have been born infected, but with enough resistance to control the powers allotted them from the infection. These children are recruited in fighting back against the parasites (who somehow manage to turn their infected victims into giant insect monsters), in the defense of Tokyo.
…This premise made a lot more sense before I tried to explain it.
(Verdict, for the sake of completion: Saw the first episode. The story could be promising, but I don’t like any of the characters. Seriously, what’s up with the eight year old who keeps propositioning a twenty-three year old? And the coroner was interesting for about three seconds, when she used a partly dissected corpse to terrify the protagonist. Then she started telling him how useless he was and asking him why he hadn’t killed himself yet. I’m sorry, what? Then she goes on to offer romantic advice, and I’m not sure I even want to touch her opinions on that topic. So yeah. Not even going to give this one a chance.)
Science: A parasitic virus is kind of an oxymoron–it’s either a parasite or a virus, unless they’re talking about a parasite infected by a virus. Maybe they could have been using the word “parasitic” to just refer to a parasitic relationship between virus and host, but I don’t think so. The giant insect monsters bursting out of their human hosts is way more likely to indicate parasites than viruses. Not that any parasites I know of grow in humans until they burst out, fully formed and independent, or anything–but parasitic wasps do something similar to insects.
Parasitic wasps laying eggs inside of insects can lead to all kinds of gruesome ends for the hosts.
Particularly disturbing picture at this link. I’m not adding it to the post itself, because some people might want to be given the option of not seeing it.
Nature can be kind of horrific.
Some parasitic wasps even give their hosts a package deal–not only do they get eggs that will hatch into larvae that eat them alive, but they get polydnaviruses to boot. The polydnaviruses function to protect the baby wasps from the host’s immune response. Maybe that was what the show meant by parasitic viruses. (Although I’m doubtful.)
And I have no idea how some people could have a “resistance” to this mechanism, other than the larvae dying inside of them–since the larvae are presumably still alive to give those people powers, and said people still need regular injections to stay alive. This aspect would make more sense if it was a virus, and not a parasite.
Maybe it’s a virus that magically turns into a parasite?
Anyway, it was at least interesting to think about.