Received Feb 4, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| COVID19 | COVID19 (COVID19 (MODERNA MNEXSPIKE)) | MODERNA | UNK | — | IM |
blood clot; cancer; can't even think straight; cold feeling/it's so cold; Injection site pain/felt pain on writing arm/ had trouble with arm; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOSIS (blood clot), NEOPLASM MALIGNANT (cancer) and MENTAL IMPAIRMENT (can't even think straight) in a 61-year-old female patient who received mRNA-1273.251 (Spikevax LP.8.1 PFS) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below. Co-suspect product included Pre-filled Syringe injection for COVID-19 prophylaxis. No Medical History information was reported. In October 2025, the patient received dose of mRNA-1273.251 (Spikevax LP.8.1 PFS) (Intramuscular use) 1 dosage form. On an unknown date, the patient started Pre-filled Syringe (unknown route) at an unspecified dose. In October 2025, the patient experienced VACCINATION SITE PAIN (Injection site pain/felt pain on writing arm/ had trouble with arm). On an unknown date, the patient experienced THROMBOSIS (blood clot) (seriousness criterion medically significant), NEOPLASM MALIGNANT (cancer) (seriousness criterion medically significant), MENTAL IMPAIRMENT (can't even think straight) (seriousness criterion medically significant) and FEELING COLD (cold feeling/it's so cold). At the time of the report, THROMBOSIS (blood clot), NEOPLASM MALIGNANT (cancer) and MENTAL IMPAIRMENT (can't even think straight) outcome was unknown and FEELING COLD (cold feeling/it's so cold) and VACCINATION SITE PAIN (Injection site pain/felt pain on writing arm/ had trouble with arm) had not resolved. No concomitant medications provided by the reporter. The patient received vaccination on Oct-2025 around the first weekend, and post vaccination the patient experienced trouble with the arm, which included significant pain that initially appeared to be a usual effect. The patient lifted the arm right away and expected the symptoms to be resolved in a couple of days. However, the pain persisted, and at the time of the report, the pain had lasted for over 90 days. The patient also reported feeling coldness at the vaccination site and experienced an inability to think straight. Due to the severe pain, the patient experienced the difficulty using the writing arm. Upon consulting with a doctor, the patient was advised to do exercises with the arm. The patient expressed concern regarding whether the symptoms were caused by a blood clot, cancer, or a lingering reaction to the vaccine. It was unknown if the patient experienced any additional symptoms/events. No treatment medications provided by the reporter.; Reporter's Comments: The benefit-risk relationship of product is not affected by this report.