Shivering electrical current /it goes throughout the patient's body all the way up to her chest. Caller reported that the patient says the feeling is around her heart.; All of the patient's body is really shivering; Patients B12 was low.; She was found to have pernicious anemia; This is a spontaneous report from a contactable consumer (patient's husband) reported his wife. A 71-years-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Lot Number: EL9267), via an unspecified route, administrated in left arm on 17Feb2021 (at the age of 71-year-old) as dose 2, single for COVID-19 immunization at clinic. The patient's medical history included ongoing diabetes (diagnosed with diabetes a long time ago, years already, many years), ongoing fibromyalgia (diagnosed with fibromyalgia a long time ago), ongoing neuropathy (her neuropathy has been going on for years and was hand in hand with her diabetes), stroke from an unknown date in May2019 to an unknown date (she had a stroke about 2 years ago), ongoing depression and anxiety (diagnosed with depression and anxiety awhile back, years ago); ongoing really bad problems with back and (years of back problems with a lot of pain). She needs to go back and see her pain medicine doctor and neurologist to see what the next step was. It was definitely recommended for her to have surgery, but he was in a wheelchair, and they don't know how surgery will deal with her condition, ongoing acid reflux (for years). Concomitant medications included amlodipine taken for blood pressure; apixaban (ELIQUIS) taken for Blood clots after stroke; aspirin [ACETYLSALICYLIC ACID] taken for Blood clots after stroke; atorvastatin {LIPITOR (ATORVASTATIN)} taken for cholesterol (she had been on Eliquis, aspirin, Lipitor; started taking them after her stroke); cyanocobalamin (B-12) taken for vitamin B12 deficiency; duloxetine hydrochloride (CYMBALTA) taken for depression, anxiety; gabapentin taken for an unspecified indication; hydrocodone bitartrate, paracetamol (NORCO) taken for Problems with back really bad; hydrochlorothiazide, losartan potassium (LOSARTAN HCTZ) taken for an unspecified indication; metformin hydrochloride (GLUCOPHAGE) taken for an unspecified indication; omeprazole taken for acid reflux; solifenacin succinate (VESICARE) taken for Bladder control; insulin human, insulin human injection, isophane (NOVOLIN 70/30) taken for an unspecified indication; oxymetazoline hydrochloride (CLARITIN ALLERGIC) taken for allergies; the patient has been taking the over the counter sleeping aid from Costco; all were from an unknown date to ongoing (she had been on Eliquis, aspirin, Lipitor, B-12, Cymbalta, gabapentin, Norco, Losartan HCTZ, Glucophage, Omeprazole, Vesicare, Novolin 70/30, Claritin and Costco for awhile). The patient previously received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Lot Number: EL9262), via an unspecified route, administrated in left arm on 27Jan2021 (at the age of 71-year-old) as dose 1, single for COVID-19 immunization. On an unknown date in Feb2021, the patient experienced shivering electrical current /it goes throughout her body all the way up to her chest. Reporter reported that she said the feeling was around her heart, all of her body was really shivering. In 2021, her B12 was low, she was found to have pernicious anemia. She was experiencing the electrical current feeling off and on. She began feeling like there was an electrical current going through her body soon after receiving the second dose of the COVID-19 vaccine but he could not say if it was a day or two or right away and that's why she thinks it might be related to the vaccine. It was stated at the end of the day it might not be related. It was reported that all of her blood work, all results were normal in exception of her B12 was low and that the patients B12 was low because she had not taken her B-12 injection for 2-3 months. She had usually administered B-12 shot but because of her reaction to the COVID-19 vaccine, the reporter was hesitant to give her the B-12 shot. It was reported that he decided to take a break from giving her the B-12 injections and then found out on a blood test that her B-12 was low. It was reported that it was probably because she had been neglected for taking injections. It was reported that they now back on schedule and he gives her injection at the beginning of the month, so she just received her Jul2021 dose of B-12. The patient underwent lab tests and procedures which included on an unknown date in 2021 blood test: normal, investigation: unknown, vitamin B12: low. As a result of Electric shock sensation, shivering patient went to emergency room visit and physician office visit. Therapeutic measures were taken as a result of patients B12 was low and she was found to have pernicious anemia. The clinical outcome of events "Patients B12 was low" and "She was found to have pernicious anemia" was unknow, while the outcome of the remaining events was not recovered at the time of reporting. Follow-up attempts are completed. No further information is expected.