ANKYLOSING SPONDYLITIS FLARE UP; fever; This spontaneous case was reported by a consumer and describes the occurrence of ANKYLOSING SPONDYLITIS (ANKYLOSING SPONDYLITIS FLARE UP) in a 65-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) for Ankylosing spondylitis.    Concurrent medical conditions included Ankylosing spondylitis.   On 12-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 02-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In 2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) Citrate free. In 2021, the patient experienced PYREXIA (fever). In November 2021, the patient experienced ANKYLOSING SPONDYLITIS (ANKYLOSING SPONDYLITIS FLARE UP) (seriousness criterion medically significant). In 2021, ANKYLOSING SPONDYLITIS (ANKYLOSING SPONDYLITIS FLARE UP) and PYREXIA (fever) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Body temperature: 103 No unit.         No Concomitant medication were reported.  It was unknown if patient was enrolled in a COVID-19 Vaccine Trial.  The reporter's causality for the event(s) of ANKYLOSING SPONDYLITIS FLARE UP and FEVER WITH COVID BOOSTER SHOT with HUMIRA(ADALIMUMAB) was a reasonable possibility.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.  No Treatment medication were reported.  Company comment-This spontaneous case concerns a male patient aged 65 years with relevant medical history of Ankylosing spondylitis reported, who experienced the unexpected serious (medically significant) AESI of Ankylosing spondylitis (ANKYLOSING SPONDYLITIS FLARE UP) that occurred on an unknown date (in Nov.2021) in the context of mRNA-1273 vaccination. Additionally Inappropriate schedule of vaccination was noted as patient had received initial two doses of mRNA-1273 at an interval of 18 days and third dose on unknown date in 2021. No further information on clinical course, investigations and treatment received was available in the report. Outcome of the event was resolved at the time of report. Relevant medical history remains a confounder to the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.   This case was linked to MOD-2021-623325 (Patient Link).; Sender's Comments: This spontaneous case concerns a male patient aged 65 years with relevant medical history of Ankylosing spondylitis reported, who experienced the unexpected serious (medically significant) AESI of Ankylosing spondylitis (ANKYLOSING SPONDYLITIS FLARE UP) that occurred on an unknown date (in Nov.2021) in the context of mRNA-1273 vaccination. Additionally Inappropriate schedule of vaccination was noted as patient had received initial two doses of mRNA-1273 at an interval of 18 days and third dose on unknown date in 2021. No further information on clinical course, investigations and treatment received was available in the report. Outcome of the event was resolved at the time of report. Relevant medical history remains a confounder to the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.