  The infinite configuration space of an integrable vertex model based on
$U_q\bigl(\hat{gl}(2|2)\bigr)_1$ is studied at $q=0$. Allowing four particular
boundary conditions, the infinite configurations are mapped onto the
semi-standard supertableaux of pairs of infinite border strips. By means of
this map, a weight-preserving one-to-one correspondence between the infinite
configurations and the normal forms of a pair of creation algebras is
established for one boundary condition. A pair of type-II vertex operators
associated with an infinite-dimensional $U_q\bigl(gl(2|2)\bigr)$-module
$\mathring V$ and its dual $\mathring V^*$ is introduced. Their existence is
conjectured relying on a free boson realization. The realization allows to
determine the commutation relation satisfied by two vertex operators related to
the same $U_q\bigl(gl(2|2)\bigr)$-module. Explicit expressions are provided for
the relevant R-matrix elements. The formal $q\to0$ limit of these commutation
relations leads to the defining relations of the creation algebras. Based on
these findings it is conjectured that the type II vertex operators associated
with $\mathring V$ and $\mathring V^*$ give rise to part of the eigenstates of
the row-to-row transfer matrix of the model. A partial discussion of the
R-matrix elements introduced on $\mathring V\otimes \mathring V^*$ is given.
