@jfannarbor the problem with AI summarizing this type of medical issue is that it pulls together all the information which is available, and some that will be old less accurate than we'd like. For example, it is known that in a significant percentage of sufferers CRP and ESR may not be elevated. Also that more people under 50 have PMR, and that flu vaccine as trigger is well supported in the medical research. This whole area is likely one where underlying causes and triggers are two different factors in the development of the illness. There seem to be many triggers all of which may be related to overloading the immune system.