If you read the original history of where the concept of zombies came from (the paper 'The Ethnobiology of Haitian Zombie' covers this, see below) the idea of biologically engineered zombies is kinda ridiculous. The idea of zombies being dead, came from toxins that slowed the heart rate down dramatically, and then the person was supposed to be dead. They then buried them as part of a ritual process. The idea of a 'mung' braindead zombie then came about because the person that was buried was starved of oxygen, and this screws with the brain. So you have two concepts: the idea of the dead returning to life, and braindead zombies. Both of which arised from a combination of neurotoxin, oxygen starvation, ritual, and folklore.
From here the concept (think of it as a meme) has mutated into zombie viral vectors, when it never was the case that the conceptual idea and myth of zombies were ever from viruses. It's a chain of piss-poor analogical reasoning and folklore perpetuated by our terrible science-lite media.
Link to paper: http://www.ncbi.nlm.nih.gov/pubmed/6668953