Dear patient, I read your concern. I will explain shortly why you have the fatigue and body pain. This is normal, because during immune responses the body temperature generally rises. Prolonged increased temperatures result in increased water loss at the cellular level and with water loss you lose the things in the water. Particularly important are potassium and sodium ions. Both are used to tell muscles to contract and low potassium levels are associated with extensive muscle use. Fever induced loss of water and potassium ions results in an artificial sensation of muscle use and associated muscle exhaustion which has pain and ache associated with it. This situation goes on for some tim even after the disease has gone. Meanwhile, what I suggest is you to take care of being well hydrated, drinking juices and eating minimum 3 meals per day. This will help you gain metabolites and energy to fight against th disease. Hope I explained what you were asking for. Best Regards, Dr. Eni