This is a great question and one that even those of us who do not have a personal brand wondering about in different degrees.  We think you should stay true to your brand and continue to share vitality with your network and clients.  It is our view that people will welcome up-beat and positive messages right now, as long as they are sensitive in tone and delivery.  Stay authentic and honest; be helpful; offer friendly relief from the dearth of difficult health and economic news.