1) Go to C:\Program Files\Symantec\Symantec Endpoint Protection Manager\Inetpub\content. Sort the sub-directories and locate the one with the latest date. Then look into its sub-directory for the latest definitions, e.g. C:\Program Files\Symantec\Symantec Endpoint Protection Manager\Inetpub\content\{C60DC234-65F9-4674-94AE-62158EFCA433}\110222036. In this directory, you will see a full.zip.
2) copy this full.zip to C:\Program Files\Symantec\Symantec Endpoint Protection Manager\Inetpub\ClientPackages\{some number}\full
3) delete the vdefhub.zip
4) rename the full.zip to vdefhub.zip.
5) regenerate your package and you will get the latest definition in it.