Originally Posted by Zardoz
Doesn't mean all the Kilingons wanted or were allowed access to it (the vaccine.)
I think the purpose of that episode was to explain why Klingons had and have ridges (and explain away TOS Klingons). All Klingons in all of Star Trek, except TOS, have ridges. Seems like the writers have been sticking with ridges and probably will continue (you never know though).