Thanks for poting your query to health care magic . I will releive your worry about your son . As I understand he is suffering from some kind of intermittent fever . I just want to know some more information that is what test your doctor have done to diagnosed Viral cause of fever and which Virus they detect and further nature of fever weather it is a continuous fever of there is a symptom free period of fever during each episode ,is there chills or rigor before episode of fever . Because as I understand it is a seasonal fever every repeated yearly and meantime he remain symptom free. So there could be possibility of allergic or parasitic fever also .so you require some more investigation to detect cause of fever . I would like to suggest you one more investigation :Complete blood Count . Untilll and unless I get the correct diagnosis I could not suggest you the medicine however you can do following : Avoid expouser of environmental polluent . Take good regular dite Avoid fasting between meals. Take mutivitamin medication containg B-complex, Vit C, Zinc ,Lycopodium,Iron two times a day for 1 month etc. review me after investigation done . feel free to contact me any time / regards, Dr.Manish Purohit