  $\mathbb{Z}_2$ topological insulators for photons and in general bosons
cannot be strictly implemented because of the lack of symmetry-protected
pseudospins. We show that the required protection can be provided by the
real-space topological excitation of an interacting quantum fluid: quantum
vortex. We consider a Bose-Einstein Condensate at the $\Gamma$ point of the
Brillouin zone of a quantum valley Hall system based on two staggered honeycomb
lattices. We demonstrate the existence of a coupling between the winding number
of a vortex and the valley of the bulk Bloch band. This leads to chiral vortex
propagation at the zigzag interface between two regions of inverted staggering,
where the winding-valley coupling provides true topological protection against
backscattering, contrary to the interface states of the non-interacting
Hamiltonian. This configuration is an analog of a $\mathbb{Z}_2$ topological
insulator for quantum vortices.
