  The paper is devoted to a computation of the Lie superalgebras of holomorphic
vector fields on isotropic flag supermanifolds of maximal type corresponding to
the Lie superalgebras $\mathfrak{osp}_{2m|2n}(\mathbb C)$ and
$\pi\mathfrak{sp}_{n}(\mathbb C)$. The result is that under some restrictions
on the flag type any holomorphic vector field is fundamental with respect to
the natural action of the Lie superalgebras $\mathfrak{osp}_{2m|2n}(\mathbb C)$
or $\pi\mathfrak{sp}_{n}(\mathbb C)$.
