Redundant Virus Definition Files in NIS 2006?

I’m running Norton Internet Security 2006, which I installed Oct-05, on Windows 2000.

 

 The virus definitions files consist of 18 separate virus definition files, created from 10/05 to 5/09, totaling 650MB in size.

Located in: C – Program Files – Common Files – Symantec Shared – Virus Definitions.

 

I am wondering if I might gain any advantages by deleting all 18, then re-downloading definitions.

Perhaps this would give fewer files, less redundancy of some components and less overall size, more operating efficiency, etc.  

 

Any pros/cons to trying this? Should I back up these 18 files first, in case I want to re-install the individual files?