  We report the results concerning the influence of vacuum polarization due to
quantum massive vector, scalar and spinor fields on the scalar sector of
quasinormal modes in spherically symmetric charged black holes. The vacuum
polarization from quantized fields produces a shift in the values of the
quasinormal frequencies, and correspondingly the semiclassical system becomes a
better oscillator with respect to the classical Reissner-Nordstr\"om black
hole.
