Protection Engine for Cloud Services 7.0.x hypervisor supportability

Hi

We're looking at our options for virus protection on one of our applications.  This is currently running on a Red Har server hosted by vsphere 4.5.  Due to customer decisions we are unable to upgrade vshere at this time.

Can anyone tell me what has driven the supportability statement that Protection Engine for Cloud Services 7.0.x is only supported on vSphere 5.x?

Is this statement only for hypervisor-based scanning or does it also apply if the protection engine is to be installed onto a virtual guest with a supported O/S which is hosted on vsphere 4.5?

Thanks

Steve