Before the outbreak I was a researcher working a cure for the rabies virus. Recently the virus has show to resist the vaccine and injection of the vaccine has been needed sooner and sooner for it to be effective. My team was making huge progress towards a cure before the outbreak happened.
Unfortunately all of my research was lost when one of the assistants of my research team began showing symptoms of the "zombie" virus and we had to evacuate. My lab was torn apart by a Disease Control team before I could recover and of the vials of cure that i had been working on. They torched the lab and all the contents inside, including my assistant's body. We were then all moved to a containment zone for a bit before more things got out of hand. Whatever this new virus is; I seem to be immune.
The symptoms that the infected show seem to be similar to the rabies virus, so I am traveling to Chernarus where I can hopefully find a cure, and if not, I will still use my minor medical training to help any survivors that I find along the way. Maybe I could perform some tests on any other immune survivors. I can't risk my own life, I am too important for that, others will do.