This is the worst possible step to take.
When I switch someone over to Mac I take the opportunity to recalibrate how they see their computer as secure. I teach them to be more aware of what they are doing and how potential viruses could infect them. I find this is 100x more effective than installing antivirus software which is shit most of the time and instills a fake sense of security.
I had a family member who would always click "OK" whenever a window popped up in Windows or would blindly enter in their password because they figured Windows was just annoying them. When they got their Mac I taught them that whenever OS X opened up a window asking for their password or asked them if they really wanted to open up a file, they should freak the hell out and be 100% sure of why that box appeared. I actually got a couple of phone calls from them asking if certain popups were OK. Sure this was annoying at first but after a week or two they started to understand why these things were happening.
The great benefit of changing their way of thinking and making security a priority was that when Flashback hit I told them that disabling plugins was one of the best ways to prevent from being infected and they immediately accepted this.
Macs are not 100% secure. No one should be under any delusions of this. But teaching people why they are not secure is the solution. Not hiding behind POS antivirus software.