Severe muscle pain, starting in upper legs, progressing upward to shoulders. Symptoms started about 12 weeks after vaccination. Up until the muscle pain symptoms became apparent (early January, 2015), I considered myself to be an active, vigorous 76 yr old, capable of most any kind of physical activity. My weight is 170 lbs and my height is 5' 10.5". at the time of the my annual physical exam (1-27-15), my blood pressure was 120/70 and my cholesterol level was 150. I have never smoked. This is the first time I have ever reported an adverse event. Symptoms: When the muscle pain started, it was in my upper legs, primarily on the right side, but eventually progressed to the upper body (shoulders), mostly on the right side. At first I did not associate it with the flu vaccine because I have been getting a flu shot every year, and have never had more than a little soreness and swelling at the injection site. Moreover, the vaccine was administered on October 4, and I did not become aware of the muscle pain until early January. I was not aware of a "high dose" flu vaccine until 10-4-15 when the nurse at pharmacy asked me if I wanted the high dose. I wondered why I had not heard about the high dose and she said they normally run out of it early in the season. I had a physical exam scheduled for Jan 27th, so I discussed the muscle pain with my doctor at that time. The pain at that time was only in the upper legs and the doctor thought I must have strained my ligaments somehow. However, I could not think of anything physically that I had done to cause it. Later, when it progressed to my upper body, the thought occurred to me that it could be associated with the vaccine, and I also thought of Guillain-Barre syndrome, which I know has been associated with vaccination in the past. In fact, in 1977 there were over 500 cases of Guillain-Barre associated with flu vaccine. I don't think I have Guillain-Barre because I have not experienced any tingling or numbness in my extremities, or any difficulty breathing, and it does not seem to be getting worse. At the peak of the leg pain, I had difficulty getting in and out of the car and it was very debilitating. Since the pain has progressed to my upper body, the leg pain has subsided somewhat. Other Medications: The only prescription drug I am taking is Levothyroxine and the dose has been stable at 88 mcg for about 2 years. I have had chronic urticaria, along with some eczema, but that has been kept under control with only a single 10 mg cetirizine tablet once a day, and occasional use of cortisone cream (OTC) when needed at a specific location. Until I started taking Ibuprofen for the current muscle pain, I had not used aspirin, ibuprofen or acetaminophen for several years, because my allergist said it would aggravate the skin problem. The attached blood test results show nothing alarming. Allergies: I have no known allergies to eggs or to any specific medicines or foods, but I do have some general allergies to house dust, pollen, etc. Infections or illnesses prior to the flu vaccination: None. Concerns: I am concerned that the Sanofi-Pasteur clinical studies of the high dose vaccine did not capture adverse events that may have occurred some weeks after the vaccination. In my experience, it is not unusual that case report forms fail to capture adverse events that later become common after the drug has been on the market for some time. A case in point is LIPITOR: When that drug came on the market the package insert said nothing about muscle pain as a possible side effect. It later became commonly known. I have never used it myself but several of my colleagues experienced severe muscle pain and in each case the doctor refused to acknowledge that it was a drug effect, and when the patient insisted on discontinuing LIPITOR, the muscle pain went away within 48 hours. Doctors seem to be the last persons to acknowledge that an adverse event might be caused by something they prescribed. In the case of flu vaccine, I think a lot of legitimate complaints may fall through the cracks, both because of the potential lag time and also because it is difficult to show a direct cause and affect relationship. In my particular case, I have no way of knowing whether the flu vaccine is definitely the cause of my muscle pain, but in my estimation it is the most likely cause.