Originally Posted by ilikebikes
The specific nature of the Kellis-Amberlee zombification virus means that any mammal weighing more than 40 lbs converts to a zombie on death, and exposure to live virus converts any living mammal large enough in minutes or seconds
The KA virus is a RNA based virus, containing sequences from natural Marburg virii and influenza virii, as well as RNA sequences modifying the protein cote of the virii such that it targets cancerous cells, or those infected with wild upper respiratory infections.
The original 'Kellis cure'/'Kellis flu' had an icosahedron-shaped capsid (the protein coat covering the RNA) of a mix of coronavirus and rhinovirus proteins, with a fifth man-made protein that was designed to increase the virus's ability to latch on to anything. This ensured a universal (or as close as one can get) infection rate.
Interactions with Marburg-Amberlee probably has changed the basic structure.
The KA virus is endemic on Georgia's version of Earth, infecting all known mammalian species. The inactive form can survive for several days on solid surfaces and can be spread via droplets and mucus suspended in the air in addition to fluid transmission and from mother to child en utero.
The active form, in addition to spontaneously developing from the inactive form when the victim dies (or rarely in other cases), can be transmitted via fluid interaction (i.e. blood, excrement, saliva, sperm, and vomit), but is not readily susceptible to droplet-based transmission (Thank God).
Occasionally exposure to the active form of the virus when one is below the amplification threshold of 40 lbs. results in the host developing an active infection only in one part of the body. For example, Georgia has active-form Kellis Amberlee in her eyes, which results in the loss of her irises to contact (and atrophying of her tear ducts). There are other reservoir conditions -- cardiac, cranial, gonadal...
The inactive form is mostly symptomless after the initial infection. Initially, the host develops a mild hemorrhagic fever -- fever, difficulty breathing, and slight bleeding from the nose or tear ducts, which clears up once the virus fully takes hold.
The active form can first be seen via neurological conditions, such as an inability to focus, a decay in memory, and in response to verbal cues -- tongue-twisters and response to name are often used as simple field tests. The pupils dilate and the eyes start drying out. Shortly after, most of the higher functions of the brain break down, as does motor control. Congrats, you have a zombie!
Treatment and Prevention
There is no known treatment for KA Virus. Bleach and other caustic chemicals can be used to destroy the virus on surfaces. Attempts to remove the virus from the host have met with failure so far and/or death of the host.
Prevention of the active form involves avoiding all contact with corpses or bodily fluids (blood, spit, vomit, etc.) that may carry the disease without proper handling equipment and ensuring that any recently deceased has its CNS damaged sufficiently that reanimation is impossible.
Rarely, persons/animals with reservoir conditions prove to be resistant to the active form of the virus. In short -- they won't spontaneously amplify and, if they do come into contact with the active form, they will go zombie but get better. Georgia is one of these.
The Kellis cure was impossible to detect in hosts via 2010 technology, even by Dr. Kellis himself. During the initial infection in India, a medical doctor jury-rigged a simple unit to monitor the active form from the blood test used to monitor glucose levels. Tests in the 2030s have increased in sensitivity to the point where false positives can happen.
tldr: If your character is a mammal, above 40 lbs., currently alive, and able to be infected by human germs, you're probably susceptible.