30 Days of Night: Dust to Dust (2007)

Sara Maguire is a nurse at a prison. When she and three guards are transferring George, a convicted murder, the group is attacked by a vampire. The prisoner escapes while the vampire manages to kill the guards and slit Sara's throat. Sara manages to escape while bleeding, realizing that she is turning into a vampire. Sara's brother Nick, an ex-cop, hears of the attack at the prison, and goes out looking for her, initially assuming that the escaped prisoner is responsible.