The incubation time for rabies is much longer. The "We're Alive" turn occurs in minutes. No known Virus or anything else can work that fast in OUR world. But, there are zombies running around, so I suspend disbelief to play along.
If we switch back towards "The Real World" and play "let's make a zombie plague..."
No DNA or Bacteria we know can spread that fast. Period.
The only thing we have that can modify behavior that quickly is a DRUG. But, the problem with a drug is that it is a one-off. Drugs do not reproduce, so each generation of victim will have a lower does. In this case, it will reach a point where it is slower acting or has less of an overall affect.
What I do is combine the two. We need a drug for fast action and we need a virus or bacteria to propigate the drug. There are many drugs that are currently being made in bacteria and viruses. But, these vectors are killed off while the drug is purified prior to use in people. But, there have been "drugs" developed that are administered by direct infection with a modified virus. The
hope is the drug will be delivered and the virus will die away or be inert. But, going back to the Math-dude from Jurasic Park, "Nature finds a way:"...
OK, another problem with viruses is that they are very small. That means they do no have a lot of "RAM" to hold new information and programs. However, some viruses contain "pseudo-genes". These things get into the human cell and change the expression level of traditional genes that we all have and use in day to day life. Although the possibility also exists that they may awaken "ancient" genes. Genes that may control agression or feeding behavior that human evolution has turned way down so we can come together as a society. Change the expression of some proteins, turn on some silent genes, drop in a gene to make a drug like LSD to really mess with perception and we are on our way to snarling ravenger with reduced cognitive abilities
I have done work on the other side of the phenomena. Modification of the flesh. BUt, Kc's "zombies" are more about cognitive function rather than physical; special zombies exempted.