Hi,
When you power on the machine after a gap of 1 or 2 weeks it’s possible that the SEPM console does not have the latest virus definitions and thereby the clients won’t have it too. The best strategy in such cases would be to upgrade the SEPM console with the latest virus definitions first. As far as the SEP clients are concerned the latest rapid release definitions should help.
The rapid release definitions can be downloaded and kept at a centrally shared location so that the clients can download that exe file(If possible may be create a script file so that the exe file is installed when the computer starts and thereby the AV/AS definitions which consume bandwidth can be updated before they contact their respective SEPM) and update their definitions, by doing so it would reduce the traffic in the network between the SEP clients and the SEPM, because when the SEP clients contact the SEPM, the SEPM checks with its own database for the version of definitions available and if the SEP client has the latest or a day old definitions, it distributes the updates which are a few KB’s in size, however if the SEP client has definitions which are a week or two old, then the SEPM will dispatch the FULL.ZIP file and the size can be around 50 to 70 MB’s(Approximate value, it may vary) which will consume a lot of bandwidth.
Reference Article: Managing SEPM & SEP after vacation
http://www.symantec.com/connect/articles/managing-sepm-sep-after-vacation