avg virus vault help needed?

You haven't said what these malware are and so I can't help you if they are safe to delete. If you delete them, you could seriously compromised your computer or make one of your program instable because they could be false positives or infected critical system files. The accepted practice is to quarantine them, submit them to AVG for analysis and leave them in the vault for a while and keep an eye on your computer and your programs if they are running fine.

It would be a good idea to investigate further of these detected malware by searching on the net of what they do and how they got there and do you need to take further actions, for example, if they are malware that log your keystrokes, you may want to change your old passwords.

If they are safe to delete or remove then they will be gone from your hard drive completely and irreversibly. So what are they?

If they're part of a program that's been infected then it will bollox that program if you delete them get a better AV that can clean files

I have dozens there .. I just leave them ... Don't come back again