This was a civilian programme. The claim was that by trying animal viruses in humanised mice they could predict which ones were likely to spill over to humans, and prepare, with treatments and vaccines. The motivations were the original SARS, MERS, Ebola etc.
Backfired a bit, I’d say.
There are quite a lot of these BSL4 labs all over the world. But part of the problem at WIV was that some of the work was being done at just BSL Level 2.
You can order the humanised mice over the internet. You can have bits of DNA synthesized by providing the genetic sequence, and the company will post them to you; transfer them to your own cell cultures at home. There’s a whole hobbyist amateur genetics community working in their own kitchens. I kid you not.