  There is a surprising isomorphism between the quantised universal enveloping
algebras of osp(1|2n) and so(2n+1). This same isomorphism emerged in recent
work of Mikhaylov and Witten in the context of string theory as a T-duality
composed with an S-duality. We construct similar Hopf superalgebra isomorphisms
for families of pairs of quantum affine superalgebras. An immediate consequence
is that the representation categories of the quantum affine superalgebras in
each pair are equivalent as strict tensor categories.
