Anti vires software for MacBook???

Unless you're running a copy of Windows as a Boot Camp partition, or in a VM such as Parallels, then you can't transfer over the Windows version of McAfee AntiVirus, or any other Windows software. It won't run.

OS X has some built in protection which it updates in the background whenever you're connected to the Internet. For a stand alone AV, the free ClamX is probably the best choice. It doesn't bog the system down like other AV software is it kept up to date.

As long as it's paid for, then all you should need to do is download the Mac version of McAfee. May as well. After that though, I'd see no reason to keep up the subscription when the excellent ClamX is free.

I am assuming it is advisable to have an anti virus package installed?

Most Mac users don't run AV software at all. There's no great need to - yet. There has never been, and still is no actual virus that works in OS X. I haven't had AV software on any Mac I've owned. And that's well over 15 years.

The main thing to do is watch out for Trojans, which are growing at kind of a fast rate since that's currently the only easy way to infect a Mac; by getting you to install something. Stay far, far away from torrents. That's where most Mac malware is. It's stuffed into illegal software downloads. You install Photoshop, or whatever, but also whatever else is in the installer package. Once you enter your admin password to allow software to install, it has full permission at that point to install anything in the installer. It doesn't need to ask you again for things you didn't know about.