After you have switched to the new active database, you must decide what to do with the old active database.
Bring the database online as the new standby database and resume the connection so that Replication Server can apply new transactions, or
Drop the database connection using drop connection, and add it again later as the new standby database. If you drop the database, any queued messages for the database are deleted. See Replication Server Reference Manual > Replication Server Commands > drop connection.