  We present a quantum kinetic theory for spin-$1/2$ particles, including the
spin-orbit interaction, retaining particle dispersive effects to all orders in
$\hbar$, based on a gauge-invariant Wigner transformation. Compared to previous
works, the spin-orbit interaction leads to a new term in the kinetic equation,
containing both the electric and magnetic fields. Like other models with
spin-orbit interactions, our model features "hidden momentum". As an example
application, we calculate the dispersion relation for linear electrostatic
waves in a magnetized plasma, and electromagnetic waves in a unmagnetized
plasma. In the former case, we compare the Landau damping due to spin-orbit
interactions to that due to the free current. We also discuss our model in
relation to previously published works.
