He tested positive for COVID-19 virus; On 26JUL2023 routine pre surgery lab works revealed that his platelets were 45. Ten days later, they repeated the lab works and his platelets were 50. The patient was told that his platelets were clumping up.; This spontaneous case was reported by a patient and describes the occurrence of PLATELET COUNT DECREASED (On 26JUL2023 routine pre surgery lab works revealed that his platelets were 45. Ten days later, they repeated the lab works and his platelets were 50. The patient was told that his platelets were clumping up.) and COVID-19 (He tested positive for COVID-19 virus) in a 78-year-old male patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (batch no. 045H22A) for COVID-19 prophylaxis.     Concurrent medical conditions included Ragweed allergy.    On 20-Apr-2023, the patient received sixth dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) 1 dosage form. On 26-Jul-2023,  after starting mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)), the patient experienced PLATELET COUNT DECREASED (On 26JUL2023 routine pre surgery lab works revealed that his platelets were 45. Ten days later, they repeated the lab works and his platelets were 50. The patient was told that his platelets were clumping up.). On 12-Aug-2023, the patient experienced COVID-19 (He tested positive for COVID-19 virus). The patient was treated with NIRMATRELVIR, RITONAVIR (PAXLOVID) for COVID-19 treatment, at an unspecified dose and frequency. At the time of the report, PLATELET COUNT DECREASED (On 26JUL2023 routine pre surgery lab works revealed that his platelets were 45. Ten days later, they repeated the lab works and his platelets were 50. The patient was told that his platelets were clumping up.) and COVID-19 (He tested positive for COVID-19 virus) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In January 2023, Platelet count (150-400): 160. On 26-Jul-2023, Platelet count (150-400): 45. On 12-Aug-2023, SARS-CoV-2 test: Positive. In August 2023, Platelet count (150-400): 50 (10 days later from 26-Jul-2023). On 24-Aug-2023, SARS-CoV-2 test: Positive. On 01-Sep-2023, Platelet count (150-400): 198. On an unknown date, Body temperature: was up for few degrees, within 30 hrs temperature was came down..     For mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (Unknown), the reporter did not provide any causality assessments.   No concomitant medications were reported.   It was reported that patient had a slight adverse event with the vaccine and the virus. The platelets have consistently been 230-235, they were unable to get an accurate reading because the platelets were clumping. Instead of using EDTA tubes, they used sodium citrate tubes. Platelets have dropped and clumped. Patient was tested positive twice and received Paxlovid and quarantined second time. It was reported that patient had a planned surgery at the end of the month for hernia and thinking to go through with due to the platelets clumping. On 12-Sep-2022, the patient received 5th dose of moderna vaccine (batch/lot number: A57148B). On 26-Jul-2023, routine pre surgery lab works revealed that the platelets were 45. Ten days later, they repeated the lab works and platelets were 50. It was told that patient's platelets were clumping up.  On Sunday morning, 10-Sep-2023, patient was listening to ABC on TV, and they said that COVID-19 vaccine increases Fibrin or Fibrinogen production. They did not mention any specific COVID-19 vaccine. They did not mention MRNA. patient was wondering if that is what is happening to him and queried whether it is related to monovalent or bivalent vaccine.   This case was linked to US-MODERNATX, INC.-MOD-2023-740180.   Most recent FOLLOW-UP information incorporated above includes: On 12-Sep-2023: Live FU received: non-significant information was updated. On 13-Sep-2023: Live FU received: non-significant information was updated.; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-740180:Case 2 (Moderna Bivalent vaccine)