For detailed up to date information on Understanding Autoimmune Disease Research read the September 2021 issue of Scientific American. It is unlikely that you will find any other source which is pretty much understandable and really well organized. Still, the Immune system is very, very complicated, so don't expect to understand every little detail of the currently understood mechanisms discussed, but the overview and what we currently know, and what we don't know is very well presented. I know that I learned a lot.
This issue has a picture of the Planet Venus, but on the bottom left corner it says: The New Science of Autoimmune Disease
PS I got my Pfizer booster shot from a local pharmacy and other than some soreness at the injection site there was no issue.
Keep Safe