  This paper deals with vector linear index codes for multiple unicast index
coding problems where there is a source with K messages and there are K
receivers each wanting a unique message and having symmetric (with respect to
the receiver index) two-sided antidotes (side information). Optimal scalar
linear index codes for several such instances of this class of problems for
one-sided antidotes(not necessarily adjacent) have already been reported. These
codes can be viewed as special cases of the symmetric unicast index coding
problems discussed by Maleki, Cadambe and Jafar with one sided adjacent
antidotes. In this paper, starting from a given multiple unicast index coding
problem with with K messages and one-sided adjacent antidotes for which a
scalar linear index code $\mathfrak{C}$ is known, we give a construction
procedure which constructs a sequence (indexed by m) of multiple unicast index
problems with two-sided adjacent antidotes (for the same source) for all of
which a vector linear code $\mathfrak{C}^{(m)}$ is obtained from
$\mathfrak{C}.$ Also, it is shown that if $\mathfrak{C}$ is optimal then
$\mathfrak{C}^{(m)}$ is also optimal for all $m.$ We illustrate our
construction for some of the known optimal scalar linear codes.
