If you have a boot virus, then yes, a boot virus can survive a re-format, because it may be hiding in the master boot record. With a boot virus, you would have to zero out the drive, fdisk, format, and re-install your operating system. Zero filling a drive puts the drive back into like-new condition, and wipes all info from it. If you have re-formatted your hard drive, then I would guess you have already lost all the data that you would have wanted to save, so a zero fill will do you wonders.
You can download a zero fill program called boot and nuke here:
http://dban.sourceforge.net/
You will need a floppy to download to, and boot your computer with it.