The ones you had to wait for in the west were mRNA vaccines. They are newer, more complicated, and in theory customisable to a wider range of infections. While I'd love to see these opened up and used for their full potential I can see why the pharma corps don't want that.

While I haven't looked, I'll bet that the Cuban ones were"simply" using a deactivated virus - which is less effective and especially less effective against mutated strains.