Slipstream VIRSCAN.zip into Silent SEP Install?

Hello,

Is there a way to add updates from the most recent VIRSCAN.zip to a silent install of SEP 12.1.5? We deploy our Windows 7 image in the field from MDT and would like to have the mose current definition file "slipstreamed" into the inital install. We currently add the update as a second applcation in MDT, after the main install. We download the update from http://www.symantec.com/security_response/definitions.jsp

Any quesitons let me know.

Thanks.