Do you mean that the "i" icon for the VRDB hasn't yet appeared (animated), or that it has, but hasn't finished doing its thing? If the second, don't worry about it. It checks/builds files fairly frequently and for a while, following a new install. If the former, right click the Avast icon, and under VRDB, check that the icons are not merged. If you want you can also command it to build the VRDB from that menu.
(If you do that, and it doesn't build - the icon will become rather animated - then there is a problem with it.)