I found this good video by Trace Dominguez. He gives a good overview and also mentions a bunch of new studies that are being done https://www.youtube.com/watch?v=dpjGLLbWZJ0

Something I never seem to hear explained: What IS long COVID. Is it damage to lungs, is it a change in the behavior of the immune system, is it something that happens in the cells? Where in the body is it hiding? Is this something we just don’t know yet?