her neck is stiff; pain directly beneath her left shoulder blade; aches and pain and pain in shoulder.; pain in both sides of her neck/Left side neck pain/Right side neck Pain; muscle pain; had discomfort in her upper arm where shot was gave; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 75 year-old female patient received bnt162b2 (BNT162B2), administered in arm left, administration date 01Mar2021 11:00 (Lot number: EN6205, Expiration Date: 30Jun2021) at the age of 75 years as dose 1, single for covid-19 immunisation. Relevant medical history included: "Bartter Syndrome" (unspecified if ongoing); "angina" (unspecified if ongoing). Concomitant medication(s) included: POTASSIUM CHLORIDE, start date: 2001. The following information was reported: NECK PAIN (non-serious) with onset 02Mar2021, outcome "recovering", described as "pain in both sides of her neck/Left side neck pain/Right side neck Pain"; PAIN (non-serious) with onset 04Mar2021, outcome "not recovered", described as "pain directly beneath her left shoulder blade"; MYALGIA (non-serious) with onset Mar2021, outcome "unknown", described as "muscle pain"; INJECTION SITE DISCOMFORT (non-serious) with onset Mar2021, outcome "unknown", described as "had discomfort in her upper arm where shot was gave"; ARTHRALGIA (non-serious) with onset 03Mar2021, outcome "not recovered", described as "aches and pain and pain in shoulder."; MUSCULOSKELETAL STIFFNESS (non-serious) with onset 05Mar2021, outcome "unknown", described as "her neck is stiff". Therapeutic measures were taken as a result of neck pain, pain, myalgia, injection site discomfort.  No follow-up attempts are possible. No further information is expected.  Additional information: She has been locked in her house for over a year with her dogs she just doesn't go anywhere. Reported she has been on potassium for about 20 years Has to take potassium or she winds up in the hospital with potassium transfusions. She received the first dose of the Pfizer BioNTech COVID-19 vaccine in her left arm on Monday. Caller stated that after she started to experience pain in both sides of her neck. She states it started on the left side on Tuesday and moved the right side on Wednesday, and on Thursday she experienced pain directly beneath her left shoulder blade. Caller stated she has a couple of questions about the aches and pains from the vaccination she received Monday. She took the vaccine well, it didn't bother her, she reported she has muscle pain in both side of her neck. She stated it started on left side and the next day it was on the right side also. Caller stated she received her vaccine on Monday and the discomfort started Wednesday. Patient Details: Height- caller stated she keeps shrinking. Caller stated that doctor does not know about the side effects she has experienced. Caller reported she has not really been sick just had aches and pain and pain in shoulder. Caller reported she was excited for next vaccine. Caller reported Tuesday she had discomfort in her upper arm where shot was gave but nothing she was paying terribly much attention to. Caller reported her neck has improved but her shoulder was still the same. Caller reported her neck was stiff today, states she was not good at remembering pains. Caller stated she does not have any medical conditions she would like to report but does mention they suspect she may have Bartter Syndrome and says she has not been told anything else. Event Details: Adds more or less the day the neck pain started on Tuesday or Tuesday evening, other than the discomfort at the shot site really didn't have anything. History: Caller reported she had no family history or medical conditions earlier in the call but stated now that she has angina which is related to her emotional stress. Treatment: Yesterday she took a nitro pill just to make sure it was not angina or cardiac related. Clarified with call how she had been on nitro since she previously reported no medications. She stated she was in her late 40's when she started taking it for her angina. Caller stated later in caller that her family, then clarifies her mother's family has a long line of sudden cardiac death. Flu shot was in October. The patient had not received any other vaccine within 4 weeks.