The leading long-distance 1-loop quantum corrections to the Coulomb potenti
al are derived for scalar QED and their gauge-independence is explicitly ch
ecked. The potential is obtained from the direct calculation of the 2-parti
cle scattering amplitude, taking into account all relevant 1-loop diagrams.
Our investigation should be regarded as a first step towards the same prog
ramme for effective Quantum Gravity. In particular, with our calculation in
the framework of scalar QED, we are able to demonstrate the incompleteness
of some previous studies concerning the Quantum Gravity counterpart.