Where do Special Infected come from?

[Khajiit]

I have always been wondering where do special infected come from. I mean, ok, zombies are infected humans, but how were the special created? I seriously don't now if there is an official article by Valve, explaining this, but if not, I want to imagine a story :D
All I can say is that they were exposed to radiation or were mutants before the infection and this caused this kind of mutation after the infection. But still, this theory can somehow explain the Hunter, Smoker or even the Witch, but it can't stand for the Tank, the Charger, the Boomer or the Spitter.
That's just my opinion so leave a comment below with yours or just corect me if there's an actual official explanation about them by Valve.

[Dr.Wh0]

The below article may give you some ideas.
http://left4dead.wikia.com/wiki/Category:Special_Infected

[Keep Smiling]

Stronger, more long-term infections, maybe?

[Khajiit]

@{Splash} So you say that "more long-term" infection can cause mutation, too? It could stand, bad I believe you turn into a zombie gradually after the infection. so we have to assume that something during the tranformation caused them to be like that. Maybe radiation, as I said, or maybe wrong medical use?
@blazinallyall Well, I didn't find something specific, so if you want you can quote some parts here to read :)

[MunkeyThrust]

Well the boy zombie loves the girl zombie very much...........

[Rhysavus]

Well if I had to assume.

Witch - I suppose could come from a previously depressed or socially rejected person. This would explain the odd appearence of the witch in terms of dress and hair style (Before you get on me about that, I'm talking from the "2 weeks after first infection" standpoint)

Tank - I'd easly go with mutation from excessive steroid usage. Combining a virus that mutates the heart rate to superhuman standards and then shoving in steroids could trigger a catalyst with the virus causing the extreme muscle build-up.

Hunter - This is a little harder to comprhend, butI would go with a lazyman excuse of having a bodybuilder. Not necessarily as extreme as the tank (I.E. not taking steroids), but simply in an extreme state of fitness. Whereby the enhanced capabilites of the virus would make his legs work just enough to go flying around.

Boomer - Medical world is full of virus having catalyst effects with fat tissue and excessive body mass. Easily attribute to previous lifestyle. (As an explanation for the Bile attraction, humans are naturally drawn to salty, sweet, and fatty foods. And since the Boomer is a high concentration of all these things, it would make sense for the zombies to go crazy for it.)

Screamer - Not much thought here. Stereotypical psychopath under the effects of intense rage would cause that screaming effect since he can't openly attack you.

Charger - This one took a little bit to type. But i will easily go with the current joke of..... well... how he got 1 arm much bigger.

Spitter - I would assume an alcoholic background. This would attribute to the odd focus on the stomach, and I don't think the "hillbilly" type would be factored into any other extreme amount of drink apart from beer/liqour/whatever.

Smoker - Smoked a lot. What can I say? As for the extreme tongue length, it could be a reaction of the tissue in his mouth from having smoked, thereby making an unkown mutation with the virus.

[Khajiit]

Well, [WRM] Warhawk 141, this was a good one. Since there is no official details we can make some :D
Now, who's the screamer? Seriously all these months playing Left 4 Dead 2 (I don't say I'm a pro or something), I haven't seen him.

[Rhysavus]

The Screamer was a Beta concept for L4D1, his skill rounded around that when seen by the Survivors, he would emit a Scream that would serve like a Boomer Vomit in that it would attract a horde.

However, as his purpose was t then run away, he was cut from the game as Testers found it too difficult to chase the thing through mobs of infected while he simply calls more.

[Khajiit]

So I can't see him in-game. Too bad. Anyway, any other interesting theories, guys? :P

[Rhysavus]

Pick a theory for something and I'll give input!

[Khajiit]

Well I think you already gave a lot info about this. I'm asking other guys to write their opinion on this.

[Khajiit]

Here's another question. Do special infected actually respawn/come back to live, or they are different infected people. If so, how do we have the same mutations and not different kinds with different grade of mutation?

[dance for food]

Originally posted by WRM Warhawk 141:

Pick a theory for something and I'll give input!

there types of people a charger is a farmer a jockey is a miget a tank is a body builder a hunter is a hunter a spitter (I'm not sure about spitter)

[Khajiit]

Originally posted by (admin):

there types of people a charger is a farmer a jockey is a miget a tank is a body builder a hunter is a hunter a spitter (I'm not sure about spitter)

I can believe that. The charges does look like wearing a farmer's clothes and the jockey looks like a midget. The spitter can be an alchoholic like Warhawk said. The Hunter, though -I insist- looks like a parkour guy.

[Lucky 13]

I think, the virus combines with substances in the body of the infected.
Boomer - Fat or a hormone which you produce while eating, I guess
Witch - Antidepressants or parathyroid hormone
Tank - Steroid
The Hunter - Cocaine, Speed, Heroine or an other drug, maybe Coffeine
Smoker - Nicotine
Spitter - I think Spitters were pregnent woman which were infected, so I think HCG-Hormone (Pregnacy-Hormone)
Charger - I can't really find a substance which would explain a mutation like this, maybe proteins or something
Jockey - ?

[Bikes]

The most likely answer is that it's a mutated strain of the virus, Bill notes that "they're changing" when they see a boomer body in the intro to L4d1, and since that's 2 weeks in it's unlikely that the SI were just all hiding until then.