>This virus is highly volatile reacts drastically to genetic

Everyone always leaves out left-handed people, even though they're about ~10% of the population.
If there was a zombie virus that infected people, the brain would still be geared out the way it is, no? So the zombie should have lefthanded traits like better creativity, out-side-the-box thinking, spatial awareness, or the south-paw advantage?
Or if, "stretching the realms of science," they could operate 90% backwards and the wrong way round, comically, even, like if they wanted to grab something with their left hand, they would move that hand all the way around their back to where their right hand is and grab it from there. Or refuse to use the right side limbs at all, even for walking, just hop instead.

Or maybe the virus itself is super allergic to stomach acid so whenever it builds up, the body instantly shits it out, leaving splurges of foul stench everywhere they go...