lost consciousness; diagnosed with Venous Sinus Thrombosis; very bad vertigo since receiving the Moderna vaccine/it has been serious; Headache; Blood clot; This spontaneous case was reported by a consumer and describes the occurrence of CEREBRAL VENOUS SINUS THROMBOSIS (diagnosed with Venous Sinus Thrombosis), LOSS OF CONSCIOUSNESS (lost consciousness) and THROMBOSIS (Blood clot) in a 69-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 025A21A and 610M20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Breast cancer (had breast cancer 17 years ago but had not had any problems since then). Concurrent medical conditions included Myelodysplasia and Osteopenia. Concomitant products included EPOETIN ALFA (PROCRIT) and CITALOPRAM for an unknown indication.   On 06-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 06-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 10-May-2021, the patient experienced LOSS OF CONSCIOUSNESS (lost consciousness) (seriousness criteria hospitalization and medically significant). In May 2021, the patient experienced CEREBRAL VENOUS SINUS THROMBOSIS (diagnosed with Venous Sinus Thrombosis) (seriousness criteria hospitalization and medically significant). In 2021, the patient experienced THROMBOSIS (Blood clot) (seriousness criterion medically significant). On an unknown date, the patient experienced VERTIGO (very bad vertigo since receiving the Moderna vaccine/it has been serious) and HEADACHE (Headache). The patient was hospitalized on 10-May-2021 due to CEREBRAL VENOUS SINUS THROMBOSIS and LOSS OF CONSCIOUSNESS. The patient was treated with RIVAROXABAN (XARELTO) for Clot blood, at an unspecified dose and frequency; ENOXAPARIN SODIUM (LOVENOX [ENOXAPARIN SODIUM]) for Clot blood, at a dose of UNK, qwk and APIXABAN (ELIQUIS) for Clot blood, at an unspecified dose and frequency. At the time of the report, CEREBRAL VENOUS SINUS THROMBOSIS (diagnosed with Venous Sinus Thrombosis), LOSS OF CONSCIOUSNESS (lost consciousness), THROMBOSIS (Blood clot), VERTIGO (very bad vertigo since receiving the Moderna vaccine/it has been serious) and HEADACHE (Headache) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 23-Jul-2021, Magnetic resonance imaging: abnormal (abnormal) blood clot was still there.         The patient turned 70 years of age on 08-JUL-2021. On 23-JUL-2021, magnetic resonance venography (MRV) showed that the blood clot was still there. When she was on Xarelto, there was no change in the clot hence it was stopped. then she was given Lovenox for a week. After this Eliquis was started.  Company comment: Very limited information regarding these events has been provided at this time. The events are probably related to the patient's comorbidities. A causal relationship cannot be excluded for the event of headache.; Sender's Comments: Very limited information regarding these events has been provided at this time. The events are probably related to the patient's comorbidities. A causal relationship cannot be excluded for the event of headache.