You can use the Virus via another computer with the free tool Audiogridder. It allows you to stream virtual effects and instruments via a network from an old laptop or Mac Mini for example where you have connected your Virus TI to.
Or you just use one Mac with Catalina or the next iteration of macOS, but in order the use the Virus TI on one computer you need a little bit more work:
First you install the free VM manager https://www.virtualbox.org/ or VMWare, install Windows 7 or something similar in it, install the Virus software there.
Connect the Virus via USB to your Mac and let VirtualBox use that USB connection. Install Audiogridder on both the Windows 7 VM and macOS.
Your VM and macOS can communicate via a virtual network (which is created by VirtualBox). With AudioGridder you can then use the Virus TI in you macOS Catalina DAW.
If you use two Macs, remember you can create a network over Firewire or a Thunderbolt cable if you want to.
Could you please give a detailed step-by-step instruction? I've managed to install Win10 on WMware, run Audiorgidder server on Win and a VST on Mac, but still can't make vst communicate with server... Feels like i have to shit on my face to use my TI