I've already looked into that to some extent. I am not a scientist but from what I've figured is that it's true a virus can't be isolated. They do, what I'll call eye of newt experiments until they build a replica of the virus. When they talk of having isolated part of the virus, they mean they've reconstructed a feature of a virus. Sure, you can build your own that way, which is basically what they did with covid and it's variants but somewhere in nature, at some point in time, these viruses or other pathogens had to exist for them to be able to isolate the actions contained within to make construction of, or replication of, possible, whether in whole or in part somewhere along a natural chain, or from a natural chain.