Double vaccinated, close contact delta, negative. Better protected as a result?

[Lelivre]

Does anyone know if a vaccinated person comes into close confirmed contact with delta and then doesn’t become unwell, if this boosts immunity in some way at least temporarily.

I’m asking for an elderly family member. It was an MRNA vaccine.

I have been wondering this too. Dh and both dc got covid but I, double vaccinated with Pfizer, didn't. Did the vaccine work as it should or didn't I catch it all?