  The superselection structure of $\son$ WZW models is investigated from the
point of view of algebraic quantum field theory. At level $1$ it turns out that
the observable algebras of the WZW theory can be constructed in terms of even
CAR algebras. This fact allows to give a formulation of these models close to
the DHR framework. Localized endomorphisms are constructed explicitly in terms
of Bogoliubov transformations, and the WZW fusion rules are proven using the
DHR sector product.
  At level $2$ it is shown that most of the sectors are realized in
$\HNSh=\HNS\otimes\HNS$ where $\HNS$ is the Neveu-Schwarz sector of the level
$1$ theory. The level $2$ characters are derived and $\HNSh$ is decomposed
completely into tensor products of the sectors of the WZW chiral algebra and
irreducible representation spaces of the coset Virasoro algebra. Crucial for
this analysis is the DHR decomposition of $\HNSh$ into sectors of a gauge
invariant fermion algebra since the WZW chiral algebra as well as the coset
Virasoro algebra are invariant under the gauge group $\Oz$.
