Sorry to burst the bubble, but while there are a lot of viruses for Windows, those over achievers are producing viruses for the mac as well. I am not sure why they get their jolly's that way, Macs can get viruses. Sadly, your MacBook, iMac, or Mac Mini can all get infected with malware. Macs are less vulnerable than Windows computers, but viruses and hackers can successfully attack them too.
So, no, Macs are not immune to viruses. And as they become more popular it will become ever more apparent just how dangerous this myth is. If you're a Mac user or your employees use them in your business, it's better to install anti-virus software than it is to rely on blind faith.
Now that is for viruses. As for keylogger, trojans, denial of service, those are a whole different breeds.
Apple claims they have protection on their now and then updates, but if something creeps up today, and you get it, betting it won't be tomorrow before they cure it.
So it is up to you if you want to trash your antivirus/malware software. Go for it. ME? I got the bitdefender total security suite and update my browser and avoid opening up mail with "click here" or any of the usual funnies. I use bitdefender because it is a low foot print , that is doesn't gobble up my resources, works in the background and so far I am doing just fine.
Others may never have a virus,trojan or any malware and not have protection. It is like driving a car, you don''t need insurance (although some states say you do) and you can drive 60 years and never have an accident. But you have the insurance, just in case something remotely might happen.