Alright guys, here is something I have thought about, something wrong with the movies and then fun thoughts on my own. Read em and comment if you wish, make your own theories or diss mine...don't be mean about it tho ok.
The virus starts out, spread by contact through the blood right, bites, scratches you know. Ok, well bugs. Mosquitoes and fleas and any other blood sucking insect that can transfer disease and virus would basically screw everyone over and the movies don't mention that. BUT ok say there are some that are immune to the direct blood transfer of the virus. What about when it becomes airborne? What about when the water becomes contaminated? As the disease mutates the ways of it being transferred are likely to grow.
Now animals, we have all seen the zombie dogs in movies, yes of course. Now where are the test animals like the chimpanzees and rats and stuff? (I just watched Planet of the Apes ok) what about cats, all other animals that have probably been bit or contaminated. Why don't we see them? Or would they also be there, like infected and after other animals? An infected dog is one thing, tigers, lions, any manner of large cat or predator would really do us a number.
(ok that is it for now, i might add later upon others criticisms and theories.)