That really is a matter of decision and choice rather than being able to or not. If 80% of people get two doses vaccination before the efficacy wanes drastically, the spreading can be stopped. It would not be possible if the vaccination process drags on forever in many countries.I don't think the vaccines were meant to stop the spreading. It reduces the chance. But not stop it. The main point of tge vaccines is to reduce hospital treatments as your own body's defences can cope tie to one has been vaccinated.
Actually, it does not matter if it is vaccine or lock-down, any measures that are carried out quickly and last long enough would be able to stop the spreading. China's lock-down in 2020 in less than 6 months have proven it.
What the word is doing except China is like trying to fill a leaking bucket, it will never be full.