Yes the files can be deleted
It is not possible to redirect them as the path is specfied by design
Growing .vdb and .tmp means that there could be a possibilty that the virus defntion could have corrupted.
in order to delte the files you have to stop Symantec AntiVirus service . and delete the content of
1. Program Files\Common Files\Symantec Shared\VirusDefs
2. delete from <\Program Files\SAV all the files with extension *.tmp, *.vdb, *.xdb, *.wdb
3. delete the content of \Program Files\SAV \I2_LDVP.VDB\
4. delete the content of \Documents and Settings\All Users\Application data\Symantec\LiveUpdate\Downloads
5. start Symantec AntiVirus service
Go to http://www.symantec.com/business/security_response/definitions/download/detail.jsp?gid=savce
and download Symantec AntiVirus Corporate Edition Client installations on Windows platforms (32-bit)
Cheeck this too
http://cca.georgiasouthern.edu/avrun.php