Pauline Mcgreever was a human living in New York with her husband, Harrison Mcgreever. After she and her husband were found hiding in a self storage unit, they both were infected by Strigoi. Ephraim Goodweather decided to make them test subjects a clinical trial.
After she turned, Nora Martinez and Ephraim Goodweather injected her with a virus genetically-engineered to kill Strigoi but be survivable by humans. Unfortunately, the virus killed her too quickly to be useful, as any Strigoi infected would die before being able to infect others. Her now turned husband was later injected with a slower-acting version of the virus and released to infect other Strigoi.
Later, Ephraim Goodweather saw all the infected Strigoi, jumping of the roof of a building to their demise. The implication being that the Master was aware of the plan and drove his minions to their deaths to prevent the spread of the infection to the other Strigoi under his control.