  We compute the vacuum polarization of a massless minimally co pled scalar
field in a background given by a black hole with subtracted geometry. Extending
previous results for the horizon of rotating black holes with no charge, we
obtain an analytical expression for the vacuum polarization that is valid
throughout the spacetime and for arbitrary rotation and charge parameters. The
vacuum polarization diverges at the inner horizon and the quantum state cannot
be extended to the inside of it.
