Abstract: The compositions and methods are described for generating an immune response to a hemorrhagic fever virus such as ebolavirus, Marburgvirus, or arenavirus. The compositions and methods described herein relate to a modified vaccinia Ankara (MVA) vector encoding one or more viral antigens for generating a protective immune response to a member of genus Ebolavirus (such as a member of species Zaire ebolavirus), a member of genus Marburgvirus (such as a member of species Marburg marburgvirus), or a member of genus Arenavirus (such as a member of species Lassa virus) in the subject to which the vector is administered. The compositions and methods of the present invention are useful both prophylactically and therapeutically and may be used to prevent and/or treat an infection caused by ebolavirus, Marburgvirus, or arenavirus.