Received May 30, 2025
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| FLUN4 | INFLUENZA (SEASONAL) (FLUMIST QUADRIVALENT) | MEDIMMUNE VACCINES, INC. | UNK | — | IN / NS |
FALL; HEAD STRUCK THE FLOOR; SYNCOPE VASOVAGAL; A literature report has been received. The article was published in Vaccine. The report concerns a female adult patient. Reviewed and summarized reports of syncope after live attenuated influenza vaccine, intranasal (LAIV) administered as the sole vaccine (i.e., no concomitant injections). From June 17, 2003 (date of LAIV licensure in the US) through May 31, 2024, VAERS received 50 reports of syncope after LAIV. Nearly half (23; 46 percent) pertained to individuals 10-19 years of age. While the vast majority of reports (35; 70 percent) did not describe any injuries, 15 people (30 percent) were injured, most commonly by falling and hitting their head or face. Twenty-two people (44 percent) required evaluation in the emergency department or doctor's office, including an individual who lost consciousness while he was driving home from the vaccination appointment. He did not report any injuries, but the car was severely damaged. Nearly three-quarters of people (37; 74 percent) developed syncope within 15 min after vaccination, but fewer than half of reports (24; 48 percent) stated that the patient had waited in the observation area for at 15 min. Based on approximately 111.9 million doses of LAIV distributed in the US during the same time period, the reporting rate is approximately 0.4 per million doses, suggesting that syncope following LAIV is rare. The information summarized here may enable clinicians, patients, and caregivers to make a more informed decision regarding preventing injuries that may occur following LAIV-related syncope. Only one described an injury: an adult fell, and her head struck the floor. She required medical attention, including head CT that did not reveal any acute findings. No medical history was reported. No concomitant products were reported. The patient received Flumist Quadrivalent (influenza vaccine live reassort 4v), via nasal route, for influenza prophylaxis on an unknown date. One described an injury described an injury: an adult fell (preferred term: Fall), and her head struck the floor (preferred term: Head injury). She required medical attention, including head CT that did not reveal any acute findings. On an unknown date, the patient experienced syncope vasovagal (preferred term: Syncope) Of the 50 reports of syncope, 43 stated that the person had recovered by the time the report was submitted, and 7 reports did not indicate recovery status. Treatment of syncope included observation, repositioning, and encouraging the person to eat or drink. Of the events that were not deemed to be vasovagal syncope, most were near-syncope, allergic reactions, seizures, or other conditions (e.g., migraine headache). Notably, near-syncope was sometimes associated with falls or other injuries, i.e., people who experienced vasovagal responses sometimes fell, even if they did not actually lose consciousness. The outcome of the event(s) of fall, head struck the floor and syncope vasovagal was unknown. The events were considered serious (Medically Significant). The reporter considered that there was a reasonable possibility of a causal relationship between Accuspray Single Dose and the following event(s): fall, head struck the floor and syncope vasovagal. The reporter considered that there was a reasonable possibility of a causal relationship between Flumist Quadrivalent and the following event(s): fall, head struck the floor and syncope vasovagal. The company physician did not consider that there was a reasonable possibility of a causal relationship between Accuspray Single Dose and the following event(s): fall and head struck the floor. The company physician did not consider that there was a reasonable possibility of a causal relationship between Flumist Quadrivalent and the following event(s): fall and head struck the floor. The company physician considered that there was a reasonable possibility of a causal relationship between Accuspray Single Dose and the following event(s): syncope vasovagal. The company physician considered that there was a reasonable possibility of a causal relationship between Flumist Quadrivalent and the following event(s): syncope vasovagal. Laboratory values are available. Device Information: Combination Product Report: Yes Product As Reported: Flumist Quadrivalent Brand Name: FLUMIST QUADRIVALENT Product Role:Suspect Manufacturer Name:ASTRAZENECA Labeled for single use:No Authors comment: Syncope after LAIV/LAIV4 is rare, and related injuries are even less common. Nevertheless, since syncope-related injuries are potentially preventable, we believe that the information summarized here may enable clinicians, patients, and caregivers to make a more informed decision regarding preventing injuries that may occur following LAIV-related syncope. Minor correction on 18-Sep-2024: Vaccine reporter added. narrative updated. Minor correction on 30-Sep-2024: Vaccine field updated due to NACK Minor correction on 31-Dec-2024: Case needs to be re-routed Case Receipt, as the Primary Reporter´s E-mail field needs to be updated as requested by the MC. Corrected Report on 12-MAY-2025: Suspect drug recoded. Narrative updated.; Sender's Comments: Syncope, head injury and fall are not listed in the company core datasheet of flumist, influenza virus vaccine polyvalent, q/laiv. Due to limited information on circumstances leading to events, onset date and outcome of events, start date of the suspect drug, clinical course, treatment provided, risk factors, relevant medical history, concurrent conditions and concomitant medications, detailed diagnostic and etiologic workup, the evaluation did not find the evidence to exclude a causal relationship between the event (syncope) and suspect drug. The evaluation did not find evidence to suggest a causal relationship between the events (head injury and fall) and suspect drug.
Medical History/Concurrent Conditions: Antiviral prophylaxis; Flu prophylaxis (Vaccine type: INFLUENZA VIRUS VACCINE (NASAL SPRAY))
Test Name: HEAD CT; Result Unstructured Data: Result: did not reveal any acute findings