while there are quite many classical explanations of displacement current to make Maxwell's equations work, see e.g. here: Displacement current - how to think of it , it sounds just a little bit like an accounting trick. Therefore, I was thinking about a more plausible explanation and came up with the following idea:
(1) The vacuum is quantum mechanically a seething sea of virtual particles and has defintely a electric polarizability. Examples for this are positron-electron generation by high electric fields by the Schwinger effect or by photon-photon collisions (Breit-Wheeler-effects) and as well as the Uehling effect (that has an impact on the Lamb-shift of the electron).
(2) A changing electric field in time will start to polarize the virtual (charged) particles, even in vacuum, - very similar to polarization effects in dielectrics. This "motion" of virtual charges in turn consitutes an effective "virtual" current that should have the same value as the displacement current from Maxwell's equations. And also, as soon as the electric field stops to change with time, the virtual polarization will stop changing and hence no effective virtual current will flow.
Is my interpretation at least somewhat correct? And if not where did I go wrong? Thanks a lot!
Or in other words (in case my interpretation is too wrong or too confusing):
How does the standard model describe the displacement current of Maxwell's equations?