Received Feb 27, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| FLU3 | INFLUENZA (SEASONAL) (FLUBLOK) | SANOFI PASTEUR | UNK | U8832CA | IM / LA |
| UNK | VACCINE NOT SPECIFIED (NO BRAND NAME) | UNKNOWN MANUFACTURER | UNK | U8832CA | OT |
became dangerously low-pancytopenia; pain; day after the flu shot I became ill with fever (101-102); headache/ headaches became excruciating; weakness; Initial information received on 25-Feb-2026 regarding an unsolicited valid serious case received from a patient. This case involves a 60 years old female patient who had became dangerously low-pancytopenia, pain, day after the flu shot i became ill with fever (101-102), headache/ headaches became excruciating and weakness after receiving Influenza Trivalent Recombinant Vaccine [Flublok Tiv]. The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided. On 21-Nov-2025, the patient received 0.5 ml of suspect influenza trivalent recombinant vaccine Solution for injection, Once (Unknown strength and expiry date) with lot U8832CA via intramuscular route in unknown administration site as the flu vaccine was used to prevent the flu and its symptoms (Influenza immunisation). On 22-NOV-2025 the patient developed day after the flu shot i became ill with fever (101-102) (pyrexia), headache/ headaches became excruciating (headache) and weakness (asthenia) (Latency 1 day) following the administration of influenza trivalent recombinant vaccine. On 24-NOV-2025 the patient developed became dangerously low-pancytopenia (pancytopenia) and pain (Latency 3 days) following the administration of influenza trivalent recombinant vaccine. Reportedly, The day after the flu shot patient became ill with fever (101-102), headache, and weakness. On the 3rd day, saw doctor who ordered blood tests. results were alarming (WBC of 1.9), and was sent to the ER. The blood tests revealed WBC had decreased further (1.8), and was admitted to the hospital. was there for 6 days. For 4 days, my WBCs (especially my neutrophils), RBCs and Platelets continued to drop and became dangerously low-pancytopenia, and my liver enzymes were extremely high. was very weak and had terrible headaches. While was in the hospital, patient was tested for everything-viral tests, bacterial cultures, abdominal sonogram, head CT and head MRI, and bone marrow biopsy. Nothing was ever found. They ran CBCs and panels every day, sometimes twice. They ran other tests as well. Nothing definitive was discovered. On the 4th day in the hospital, blood tests stabilized, but my headaches became excruciating. Patient was discharged 2 days later since blood tests were improving, but recovery was slow. patient was weak with terrible headaches for about 2-3 more weeks. Relevant laboratory test results included: White blood cell count - On an unknown date: 1.9 UNK [1.9]; on an unknown date: 1.8 UNK [1.8] Action taken: not applicable. No corrective treatment was received for the events. outcome was Recovered / Resolved on 23-Dec-2025 for the events. Seriousness criteria: This event (Pancytopenia) was assessed as medically significant, and all the events were leading to disability. The patient was hospitalized for all the events. from 2025; Sender's Comments: Sanofi company comment dated 26-Feb-2026: This case involves a 60 years old female patient who had became dangerously low-pancytopenia, pain, day after the flu shot i became ill with fever (101-102), headache/ headaches became excruciating and weakness after receiving Influenza Trivalent Recombinant Vaccine [Flublok Tiv]. Further information regarding allergic history, medical history, concomitant medication and tolerance, excluding alternative etiologies for the reported event are needed to fully assess this case. Based upon the reported information, the role of the suspect vaccine cannot be assessed.
Test Name: WBC; Test Result: 1.9 {DF}; Result Unstructured Data: 1.9; Test Name: WBC; Test Result: 1.8 {DF}; Result Unstructured Data: 1.8