  A measurement of the Higgs boson production cross sections via associated
$WH$ and $ZH$ production using $H \rightarrow WW^{\ast} \rightarrow
\ell\nu\ell\nu$ decays, where $\ell$ stands for either an electron or a muon,
is presented. Results for combined $WH$ and $ZH$ production are also presented.
The analysis uses events produced in proton-proton collisions collected with
the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The data
correspond to an integrated luminosity of 36.1 fb$ ^{-1}$ recorded at a
centre-of-mass energy of 13 TeV. The products of the $H \rightarrow WW^{\ast}$
branching fraction times the $WH$ and $ZH$ cross sections are measured to be
$0.67^{+0.31}_{-0.27}$(stat.)$^{+0.18}_{-0.14}$(syst.) pb and
$0.54^{+0.31}_{-0.24}$(stat.)$^{+0.15}_{-0.07}$(syst.) pb respectively, in
agreement with the Standard Model predictions.
