behind zombie lines

A deadly man made virus that had been locked up and sealed away in a secure unoccupied section of a military hospital is discovered by two medical students who share a single life goal of finding a cure for death or prolonging life. After experimenting with the virus and running several test samples, they find that the virus is the breakthrough discovery they have been seeking. They steal the virus with the intention of further development, and selling it to the highest bidder. Things backfire when they set up a meeting with an interested party. On their way to the meeting, they get into a car accident in which the container holding the virus is damaged, releasing the virus into the atmosphere. Soon, water and food supplies are contaminated creating a global pandemic. The story then shifts to a first person account told by a woman who has been caught in the middle of this chaos, which includes her daughter and two grandchildren struggling for survival behind zombie lines.