those viruses were for Mac OS 9BTW, I've been running just Macs for a long while now, and have never moved to OS X, and have never had a virus.
After 28 years as an Apple customer, I've only encountered one virus - the "WDEF virus" around 1989-1990. It spread on floppy disks. It was difficult to get rid of because we had a bunch of Macs and a bunch of floppy discs.