Discomfort in right lower back; Spasms-not external muscles but internal/Spasms become very rapid/ Spasms and pain moved up back to waist then moved to front, and continued up abdominal area stopping at rib cage; Shooting staightline pain from right of spinal chord horizontally across back and spasming area; Shooting staightline pain from right of spinal chord horizontally across back and spasming area; Shooting staightline pain from right of spinal chord horizontally across back and spasming area/ Spasms and pain moved up back to waist; Spasms and pain moved up back to waist, then moved to front, and continued up abdominal area stopping at rib cage; Spasms and pain moved up back to waist, then moved to front, and continued up abdominal area stopping at rib cage; Spasms and pain moved up back to waist, then moved to front, and continued up abdominal area stopping at rib cage; Cyst on ovary; This spontaneous case from the United States was retrieved on 04-Oct-2021 from Vaccine Adverse Event Reporting System (VAERS) (reference number: 1685020-1), reported by other non-health professional (consumer) and concerned a 75-year-old, female patient.  The patient's concurrent conditions included hypertension (HTN), atrial fibrillation (A-fib), familial essential tremors, cephalosporins, penicillin, statins, citrus, shellfish and metal allergies. The patient's concomitant medications included losartan, furosemide, potassium chloride (reported as ''KCl''), metoprolol, buspirone, vitamin B complex (vit b complex), cinnamon (cinnamomum verum), lorazepam and Eliquis (apixaban), all used for an unreported indications. The patient had regular influenza shots, annually for many years with no problems.  On 22-Oct-2020, the patient was vaccinated with Fluad Quadrivalent (influenza vaccine, inactivated influenza virus surface antigen (subunit), egg-derived, mf59; dose reported as one, route of administration: intramuscular, anatomical location: right arm; indication: not reported). The batch number reported was 279813.  On the same day, within ten seconds after receiving Fluad Quadrivalent, the patient felt discomfort in right lower back, which quickly became more severe with spasms which were not external muscles but internal. Spasms became very rapid and severe with shooting staightline pain from right of spinal cord (reported as ''spinal chord''), horizontally across back and spasming area. Spasms and pain moved up back to waist, then moved to front, and continued up abdominal area stopping at rib cage. The patient went to emergency department (ED). Upon arrival, spasms and pain continued subsiding after about 45 minutes. Electrocardiogram (EKG) was performed and the patient was monitored for vitals, with no unusual result and computerised tomogram (CT) abdomen revealed nothing unusual except for cyst on ovary. The patient did not receive any medications in ED and was discharged with no further events. Additionally, the patient visited physician's office and her doctor recommended no more quadrivalent.   On the same day, the patient recovered from all events, except from the event of 'cystic ovary' for which the outcome was not reported.   The reporter did not provide a causality assessment.   The case was assessed as non-serious.  Company comment: A 75-year-old patient developed back discomfort, muscle and abdominal spasms, as well as spinal, back, rib and abdominal pain on the same day after vaccination with the suspect product Fluad Quadrivalent. Advanced age of patient confounds causality. Computerised tomogram of abdomen revealed nothing unusual except for cyst on ovary. Causality for the reported ovarian cyst is assessed as not related due to biological implausibility. Due to suggestive chronology, causality is assessed as possibly related for all other events.; Sender's Comments: A 75-year-old patient developed back discomfort, muscle and abdominal spasms, as well as spinal, back, rib and abdominal pain on the same day after vaccination with the suspect product Fluad Quadrivalent. Advanced age of patient confounds causality. Computerised tomogram of abdomen revealed nothing unusual except for cyst on ovary. Causality for the reported ovarian cyst is assessed as not related due to biological implausibility. Due to suggestive chronology, causality is assessed as possibly related for all other events.