Unfortunately vaccinations do not prevent infection, they reduce disease (sickness). That would reduce sickness in new birds, but would not prevent continued infection or carrier status. You would certainly need to close your flock, and not allow any birds to leave. In addition, you should not go near anyone elses birds, and others who have birds should avoid your premises.
Sad as it is, only culling the entire flock then disinfecting the premises will get rid of the infection.
Sad as it is, only culling the entire flock then disinfecting the premises will get rid of the infection.