DVT/D-dimer after first vaccine dose 5750; This is a spontaneous report from a contactable consumer (patient's husband).  A 50-year-old female patient received BNT162B2, via an unspecified route of administration, administered in Arm Left on 18Aug2021 (Lot Number: FC3180) as dose 1, single for COVID-19 immunisation; apixaban (ELIQUIS), route of administration, start and stop date, batch/lot number and dose were not reported for an unspecified indication. Medical history included Hashimoto's disease from 2012 to an unknown date, history of COVID-19 from 04Jan2021 to 2021 and history of deep vein thrombosis (DVT) from 22Jan2021 to 2021. The patient's concomitant medications were not reported. The patient experienced DVT and d-dimer after first vaccine dose was 5750 in Aug2021 with outcome of unknown. The clinical course was reported as follows: Consumer calling about the Pfizer COVID-19 vaccine who says that ultimately he would want to get in touch with the medical director since he works in the industry and his wife has a history of COVID and DVT associated, and has had resolution of the disease and clots. He says that she waited until recently to get her first dose of the Pfizer COVID-19 vaccine due to her history of DVT and the unclear connection of DVTs impacting vaccine or immune system. He says his wife got a d-dimer the week after receiving her first dose, and her d-dimer was extremely elevated, to just a bit lower then when she was hospitalized with DVTs previously. He says ultimately he thinks they have got a great case that could be helpful, and also she has underlying Hashimoto's disease, and she would be willing to submit blood samples if it turns out they would be interested in having those. He says his wife's Pfizer COVID-19 vaccine card is handwritten with no NDC/EXP provided on card. Indication: He says that she got it for further protection, although disease conferred and gave some immunity she wanted further protection. He says reports are conflicting concerning recovery from diseases and full immunity and the vaccine has been studied and it was recommended by her cardiologist and primary care doctor for further protection. He clarifies that his wife tested positive for COVID 04Jan2021 from a rapid readout, which he can't remember if that was antigen or PCR, which he confirmed with his wife it was a PCR. He clarifies his wife had been diagnosed with Hashimoto's in 2012. He clarifies his wife's DVT was 22Jan, and they had confirmed DVT with multiple emboli in her lungs, and she was hospitalized. Hospitalization was before Pfizer COVID-19 vaccination. He says that the DVT was primarily her left calf, and it was the week before that the DVT developed. He clarified that the D-dimer range of 5700-6000 result was exactly 5750. He adds that patient's thyroid test result was in healthy range at that point. He thinks that the information from his wife actually could be a great help, and could just be correlated as an extreme spike with the D-dimer being a good test for underlying conditions being more susceptible to DVTs after obtaining vaccine. He says his wife's pulmonologist took her off Eliquis then waited for a month and checked her D-dimer which was then in the 300s and stayed very low post DVT. He says his wife was on Eliquis for three months, and post term of Eliquis she had a very low level for her D-dimer. No further details provided about his wife's Eliquis. He says that his wife had no other medications, conditions or tests related to her thrombosis or clotting, and in waiting to do the first dose they were just being prudent and monitored it for a week after dose for information, which is what prompted wanting to share this information. The patient underwent lab tests and procedures which included D-dimer: 5750 in 2021, in the 300s in 2021 (waited for a month and checked her D-dimer which was then in the 300s and stayed very low post DVT) and post term of Eliquis she had a very low level for her D-dimer in 2021, COVID-19 PCR test: positive on 04Jan2021 and thyroid test: thyroid test result was in healthy range at that point in 2021. The action taken in response to the event for apixaban was temporarily withdrawn on an unspecified date.  Follow-up attempts are completed. No further information is expected.