Technically, OSX is more secure than windows.
OSX is based on unix, a mature Multi-User based OS which isolates root from users, and hence prevents users from accessing/installing things they aren't supposed to.
Windows was designed as a single user OS, and hence all user actions were basically trusted.
In terms of actually fixing exploits, Microsoft has a much lower response delay and much higher response rate than Apple.
Unfortunately much of Windows exploit issues are not even Microsofts fault - many exploits actually come from poorly secured 3rd party software, something that Apple doesn't really have to deal with, because typically the MacOS is insignificant, and only a few major developers actually program anything for it, rather than every man and his dog which programs for Windows OS's.
It's the same problem with virii .. only a few hardcore major virii vendors develop for MacOs, but every man and his dog programs virii for windows, because windows is the majority market.
In the event that Apple Mac's get owned by virii, I suspect that most of the users would be at a total loss what to do, not that PC users are significantly more clued in. But on PC, you can find someone that can fix it easier/quicker than you will find someone that is a Mac administrator