That'll depend on the vaccine, it is possible that a vaccine will give protection from significant disease but not protect much against infection and thus spread.But if we don’t have mass immunisation then it’s very likely Covid will continue to spread and thus mutate, possibly making the vaccine pointless. You need the vast majority to be immunised for it to work. That’s my understanding of the science.
Until the trials are complete which should be within the next year hopefully we won't actually know what the vaccine does. But if you work in a place of high risk of catching it and it is demonstrated to protect against disease you would be pretty daft not to take it in my view.