  We compute 1-loop corrections to Lorentz-signature de Sitter-invariant
2-point functions defined by the interacting Euclidean vacuum for massive
scalar quantum fields with cubic and quartic interactions. Our results apply to
all masses for which the free Euclidean de Sitter vacuum is well-defined,
including values in both the complimentary and the principal series of SO(D,1).
In dimensions where the interactions are renormalizeable we provide absolutely
convergent integral representations of the corrections. These representations
suffice to analytically extract the leading behavior of the 2-point functions
at large separations and may also be used for numerical computations. The
interacting propagators decay at long distances at least as fast as one would
naively expect, suggesting that such interacting de Sitter invariant vacuua are
well-defined and are well-behaved in the IR. In fact, in some cases the
interacting propagators decay faster than any free propagator with any value of
$M^2> 0$.
