Received Oct 23, 2025
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| UNK | VACCINE NOT SPECIFIED (OTHER) | UNKNOWN MANUFACTURER | 1 | UNK | IM / LA |
Atrial Flutter; This 79-year-old female subject was enrolled in an open label study titled A phase 3b, randomized, open label, multi-country, multi-center, extension and crossover vaccination study to evaluate the immunogenicity and safety of different revaccination schedules and persistence of a single dose of the RSVPreF3 OA vaccine in adults aged 60 years and above who participated in the RSV OA=ADJ-006 study. The subject received the 1st dose of RSVPreF3 vaccine + AS01E (intramuscular, left deltoid) 120 µg on 07-APR-2025, for prophylaxis. In AUG-2025, between 3 and 5 months after receiving RSVPreF3 vaccine + AS01E, the subject developed moderate - grade 2 atrial flutter (Verbatim: Atrial Flutter). Serious criteria included hospitalization. The subject was treated with apixaban (Eliquis) and metoprolol tartrate. The outcome of atrial flutter was unknown. The investigator considered that there was no reasonable possibility that the atrial flutter may have been caused by RSVPreF3 vaccine + AS01E. The company considered that there was no reasonable possibility that the atrial flutter may have been caused by RSVPreF3 vaccine + AS01E. GSK Receipt Date: 17-OCT-2025 Participant reported hospitalization sometime in early August 2025 for Atrial Flutter. Participant reported that she was discharged after a one day. Follow up PCP (Primary care physician) appointment on 23 AUG 2025 where subject was prescribed Eliquis 5 mg BID and Metoprolol tartrate 25 mg BID. Participant would follow up with cardiology this month. Admitted to Medical center - records were requested to determine if any further reporting was required. AE (adverse event) was not related to study treatment. Hospital Admission date of AE: UNK-AUG-2025 Hospital Discharge date of AE: UNK-AUG-2025 SAE was not Related to Study Participation Activities other than Study Treatment. This case contains an event assessed by the investigator as a serious adverse event of special interest (AESI). This was a new disease and not exacerbation of an existing disease. Date event became serious: UNK-AUG-2025; Sender's Comments: A case of Atrial flutter, between 3 and 5 months after receiving 1st dose of RSVPreF3 vaccine + AS01E, in 79-year-old female subject. Report is inconsistent with causal relation to the vaccine product, considering implausible time to onset.