  The stability of two entangled spins dressed by electrons is studied by
calculating the scattering phase shifts. The interaction between electrons is
interpreted by fully relativistic QED and the screening effect is described
phenomenologically in the Debye exponential form $e^{-\alpha r}$. Our results
show that if the (Einstein-Podolsky-Rosen-) EPR-type states are kept stable
under the interaction of QED, the spatial wave function must be
parity-dependent. The spin-singlet state $s=0$ and the polarized state $\frac
1{\sqrt{2}}(\mid +-> -\mid -+>)$ along the z-axis\QTR{bf}{\}give rise to two
different kinds of phase shifts\QTR{bf}{.} Interestingly, the interaction
between electrons in the spin-singlet pair is found to be attractive. Such an
attraction could be very useful when we extract the entangled spins from
superconductors. A mechanism to filter the entangled spins is also discussed.
