Virus Scanner on Macbook Pro

What virus scanner are you using on your macs. I have been reading that they now should have a scanner. I use Vipre on my 'other brand'

None. There are no viruses currently existing for OS X. Don't know where you read about needing one, but it's not valid. Not only are there NO viruses now, there are no known vectors by which OS X can be attacked. Which means that scanners don't know what to scan for. So don't bother. When a virus hits OS X, the AV companies will have to scramble to look for that vector. But until then, they do nothing but identify Windows viruses usually found in emails.

As there are no viruses for Mac OS X why? If you must try ClamXAV.