Marbas said:
If we really want to be realistic, ye olde fashioned zombie outbreak probably wouldn't be sustainable. Second law of thermodynamics and all.
Except...
Let's say the T-Virus is attached to the Anthrax virus. Easily containable, it travels through the air and grows within the stomach and lungs of it's victim. The victim suffers massive internal damage over a period of time and at it's death, the stomach bursts releasing a cloud of lethal spores, which get into the mucous membranes of anyone nearby.
Oh, and it gets animals as well as humans.
Let's say the T-Virus attacks from within, like the HIV virus, and forces the white blood cells to attack healthy cells as well; whilst growing a cancerlike secondary brain at the top or base of the spine (And there's enough room there). At the moment of normal death, the secondary brain takes over and keeps the heart running, pumping adrenaline and blood throughout the system.
The body will still be starved of oxygen, and will flounder at a slow speed, but it still will be capable of the most basic thoughts; one of which will be the primal idea to save itself.
So, you've got a slow moving zombie that's desperate to find anyone, whilst silently screaming "Help me!" (voicebox will have atrophied due to the lack of moisture). It has the intelligence of a Golden Labrador and breathes almost pure Anthrax.
It's no idea of what's happening to it, because it's lost the social construct of "infection", so it will try ANYthing to get you to help it.
Oh, and if you do kill it, which requires severing the spinal cord, it's stomach contents burst like a bio-chemical bomb.
The bite just makes things 100% likely, breathing on you is 50% effective unless you can cover all your body; whilst it has the panic-strength that most people have if under severe stress.
And if you do a poll of how many 'normal' people actually believe in Zombies, it'll come out very low. They'll just think the guy is a burns victim or something and either help him or ignore them.
Then, they'll feel a little bit of a cough. Can't be much, just must be a cold.
It develops into flu, but that means a day off work. And all the family are round.
Now the family have gone, all got the flu as well. Whoops. Even the dog seems to be a little under the weather.
Stomach ache, just take some medicince, it will be gone in a bit.
Argh, got to get to the Doctor. Ring 999/911. "Hello...I need...a...."
"Hello caller? Caller? *crash* We'll send an ambulance around straight away."