back pain; This is a spontaneous report from a contactable consumer (patient) and physician via medical information team. A 66-year-old female patient received first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 m-RNA VACCINE, solution for injection, lot number: EL9263), via an unspecified route of administration, administered in arm right on 27Jan2021 (at the age of 66-year-old) as dose 1, single for COVID-19 immunization. Medical history included stroke from an unknown date in Nov2019. The patient concomitant medications were reported as none. On 29Jan2021, the patient experienced back pain. The patient mentioned that she received the 1st dose of the vaccine on 27Jan2021 and then two days later at her doctor appointment she was experiencing back pain and they gave her a steroid injection on the sacroiliac area 2 days later on 29Jan2021. She said that this was injected on 29Jan2021, dose unknown, to near her tail bone area, supposed to give at sacroiliac area. She says that the product administered was Depo-Medrol 80 mg NDC 0703005101 and administered in the joint specifically between sacro and pelvis. She said back pain she was experiencing unrelated to the vaccine. She was worried for her 1st dose because she took the steroid shot near it. She would want to know if it will affect the vaccine. Patient calling with a question who says she received her first vaccine dose 27Jan and then two days later at her doctor appointment she was experiencing back pain and they gave her a steroid injection, and she didn't realize that possibly she wasn't supposed to have that done, which she found out after her last injection, a week ago. She says a week ago a nurse asked her had she taken Acetaminophen or Ibuprofen before her last COVID shot, which she said no, and the nurse said that is good and to make sure you don't take anything unless you are experiencing discomfort, and then take it. She says that she realized maybe she should not have had the steroid injection, and now she is worried she won't be covered by the vaccine, that it may have affected its effectiveness. Steroid Injection NDC/LOT/EXP: Unknown. Caller says that this was injected 29Jan, dose unknown, it was injected to near her tail bone area, supposed to give at sacroiliac area. Patient says her second Pfizer COVID-19 vaccine dose was 17Feb, to her right arm about 10:30AM by the time registered. She says both doses were given in her right arm. She says that there are labels on her handwritten vaccine card, her name and everything was in her handwriting. She provides first dose LOT: EL9263 and second dose LOT: EN6200. She says NDC/EXP was not provided on her vaccine card. Concomitant Medications: Patient says they have not had any other recent vaccinations or started any new medications. Patient mentioned that she got the second dose of the covid vaccine on 27Jan and 2 days later she was given a steroid injection. She is concerned to get the full efficacy of the vaccine. She says that the product administered was Depo-Medrol 80 mg NDC 0703005101 and administered in the (Name) joint specifically between Sacro and pelvis. Patient wanted to know if the steroid injected will cause that she does not have the 95% efficacy of the vaccine. The reporter mentioned she got the second dose of the covid vaccine on 27Jan2021. The patient mentioned that she received the 1st dose of the vaccine on 27Jan2021 in initial report. The patient mentioned getting a dose of the vaccine on 27Jan2021 and getting a steroid injection 2 days later. However, the patient did not actually say if the dose on 27Jan2021 was her first or second dose of the Pfizer-BioNTech COVID-19 vaccine. Patient received the first dose of the Pfizer Covid vaccine in Jan and states that she had a steroid injection 2 days after for back pain she was experiencing unrelated to the vaccine. Patient stated that she contacted Pfizer and spoke with a few departments, in which one department asked for additional information. Patient stated that she contacted the specialist who performed the injection and provided the information. Patient stated her initial call was asking if the steroid injection would compromise the vaccine. Today, patient is contacting Pfizer because she received a packet in the mail a couple of weeks ago which has a lengthy survey to complete. Patient stated the reported event is listed as back pain, in which that information is incorrect. Patient stated she did not experience back pain from the Pfizer shot and does not want to complete the survey if it is based upon incorrect information for the reported event. Patient stated, I don't want to complete the survey if they think I had back pain due to the injection. Patient is calling to correct information on the report and to find out if she still needs to complete the packet that was sent to her. Therapeutic measures were taken as a result of back pain. The outcome of the event was unknown.  No follow-up attempts are possible. No further information is expected.