came down with flu type a. got a positive result on the rapid flu a test/got sick with flu; fever; severe muscle aches; lack of efficacy. got sick with flu a; Initial information received on 23-Jan-2025 regarding an unsolicited valid non-serious case received from patient This case involves a 56 years old female patient who got a positive result on the rapid flu a test/got sick with flu, fever, severe muscle aches and indicating lack of efficacy after receiving influenza USP trival A-B subvirion NO preservative vaccine [Fluzone]. The patient’s past medical history, medical treatment(s), concomitant medications, vaccination(s) and family history were not provided. On 06-Dec-2024, the patient received 0.5 ml of suspect influenza USP trival A-B subvirion NO preservative vaccine Suspension for injection (Unknown strength) with lot UT8408LA and expiry date JUN-2026 via intramuscular route in unknown administration site for Flu prevention (Antiviral prophylaxis) On 19-Jan-2025 the patient developed came down with flu type a. got a positive result on the rapid flu a test/got sick with flu (influenza a virus test positive), fever (pyrexia), muscle aches (myalgia) and lack of efficacy. got sick with flu a (vaccination failure) (Latency 1 month 13 days) following the administration of INFLUENZA USP TRIVAL A-B SUBVIRION NO PRESERVATIVE VACCINE. Relevant laboratory test results included: Influenza A virus test – On 19-Jan-2025: Positive Action taken was not applicable. It was not reported if the patient received a corrective treatment for all the events. At time of reporting, the outcome was Recovering / Resolving for all the events.