BTW, I don't subscribe to the "virus" concept as a source for reanimation of the dead--at least not so far as is concerned in the Romero-verse or any similar depiction. It makes absolutely NO sense from a medical or scientific perspective. I have, on the other hand, hatched a personal theory on the source of the reanimation of the dead and I'm currently writing a short book/report on the subject. So far, it's been a lot of fun! And, yes, it is TRUE reanimation of an otherwise dead host which is continuing to "function" based on a system other than biochemical reactions. Anyhow, a virus makes no sense because it requires a functioning metabolism to continue operation. Stop the metabolism and the body dies and so does the virus. Metabolic functions are based on wide ranging inter-related systems working in concert in order to maintain operation or "life". Disrupt ANY one of these systems and the host "dies".