There is a vaccine available, but it is controversial and some vets
do not recommend it, although others highly encourage it. The
manufacturer’s tests state that it has an efficacy rate (protection
rate in this case) of 69%. Cornell Feline Health Center then did a
study which said the vaccine failed to show any protection, and that it
accelerated the disease in 52.5% of exposed cats. However, this study
used a different challenge virus strain and the route of administration
was different than the manufacturer’s tests. The ‘real-life’
significance of this has not yet been determined, neither Cornell nor
the manufacture has received reports from the field of abnormally high
numbers of cats which get the disease as a result of the vaccine.
However, this study has caused a lot of people to swear-off the
vaccine.

It really is between an individual cat owner and their vet to determine
the whether or not to vaccinate based on the best information available
at the time.