Vaccine

Hi guys plz help. So my whole family is vaccinated w moderna and we all live together besides my brother. He had covid previously and took the Johnson and Johnson vaccine. I know the cdc says that it’s safe for vaccinated people to see each other HOWEVER I know my brother works with a lot of people, who I assume aren’t vaccinated yet. If he came to visit us (having been w nonvaccinated people) how likely is it that he would spread anything to us? I usually visit my bf who is also not vaccinated but he’s extremely cautious, so if I saw my brother who usually is with nonvaccinated people, would my brother (who is vaccinated) be able to spread it to me (also vaccinated) who then cud spread it to my bf (not vaccinated)? Or am I thinking too much lol