Hi,
You have several options available, depending upon what your requirements are. If you are looking for agent-less anti-virus protection for VM's on a host, the solution would consist of VMware Endpoint (included in vSphere 5.1 and above) AND a product from one of our AV partners (Trend Micro, McAfee, Kaspersky, etc...). If you are looking for a stateful firewall to inspect VM traffic, you can now choose between vCloud Networking & Security (which is only available as part of the vCloud Suite) or NSX, which is sold stand-alone.
Hope this helps....