low platelets thrombocytopenia; bruising on her arms & legs; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOCYTOPENIA (low platelets thrombocytopenia) in a 93-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 017F21A, 025J20A and 030L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 06-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 03-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 03-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In November 2021, the patient experienced THROMBOCYTOPENIA (low platelets thrombocytopenia) (seriousness criterion medically significant) and CONTUSION (bruising on her arms & legs). The patient was treated with PREDNISONE at an unspecified dose and frequency. At the time of the report, THROMBOCYTOPENIA (low platelets thrombocytopenia) and CONTUSION (bruising on her arms & legs) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In September 2021, Platelet count: 80 80. In November 2021, Platelet count: 15 (Low) Low.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   No relevant concomitant medications were reported.  Company comment: This is a Spontaneous case concerning a 93-year-old, female patient with unknown medical history,  who experienced the unexpected serious (medically significant and  AESI) event of Thrombocytopenia aggravated. The event occurred with imprecise time to onset after the third dose of mRNA 1273 vaccine. Patient received previously two doses of mRNA 1273 with adequate latency 11 month before the booster and the event. Patient was being monitored because of low platelet count and in September had a count of 80.000 and after the third dose she developed bruises and was found to had platelet count dropped to 15.000. She received treatment with Prednisone. The medical history of having low platelet count is a confounder for the event.   The benefit-risk relationship of mRNA 1273 vaccine is not affected by this report.; Sender's Comments: This is a Spontaneous case concerning a 93-year-old, female patient with unknown medical history,  who experienced the unexpected serious (medically significant and  AESI) event of Thrombocytopenia aggravated. The event occurred with imprecise time to onset after the third dose of mRNA 1273 vaccine. Patient received previously two doses of mRNA 1273 with adequate latency 11 month before the booster and the event. Patient was being monitored because of low platelet count and in September had a count of 80.000 and after the third dose she developed bruises and was found to had platelet count dropped to 15.000. She received treatment with Prednisone. The medical history of having low platelet count is a confounder for the event.   The benefit-risk relationship of mRNA 1273 vaccine is not affected by this report.