April 2022 - Risk of venous thromboembolism after COVID-19 vaccination

This US study looked at the occurrence of VTE before and after vaccination over a 12-month period (November 2020-2021). There were 792,010 participants who had at least one vaccination: Pfizer (452,950), Moderna (290,607) and Johnson & Johnson (48,453) with the average age being 57 years.

Results found that 772 VTE events were recorded 90 days prior to vaccination and 793 (489 had DVT and 426 had PE) events 90 days after a vaccine being administered. The overall incidence rates were similar per 1000 person-years at 4.0 pre-vaccination and 4.1 post-vaccination.


April 2022 - Risks of DVT, PE and bleeding after COVID-19

This study consisted of just over 1 million people who tested positive for SARSCoV-2 between 1 February 2020 and 25 May 2021 in Sweden and a control group of approx. 4 million participants. The results found that after having COVID-19 there was an increased risk for deep vein thrombosis after three months, for pulmonary embolism after six months, and bleeding at two months.

The study also found a higher risk for these conditions in patients with comorbidities or had more severe symptoms associated with COVID-19. Patients who had COVID-19 in the first wave also were at higher risk compared to those in the second wave.

These results provide useful information which could impact recommendations for diagnosis and preventative strategies against DVT, PE and bleeding after having COVID-19.


January 2022 - COVID-19 vaccination and cerebral venous sinus thrombosis

Cerebral venous sinus thrombosis (CVST) has been reported following COVID-19 vaccination. This observational prospective study aimed to investigate any increased risk to patients with prior CVST after receiving a COVID-19 vaccination.

Of the 62 patients with prior CVST, 43 received Pfizer-BioNTech, 7 patients received Moderna mRNA-1273 and 7 received ChAdOx1 with 5 receiving Janssen Ad26.COV2.S. From these cases, no thrombotic events reoccurred within 30 days after vaccination. Despite the small sample size of this study, the data supports that COVID-19 vaccines are safe in patients who have previously had CVST.


December 2021 - Research - COVID-19 and the risk of thrombosis

Patients hospitalised with COVID-19 are at risk for thrombotic events after discharge.

The study found that extended post-discharge thromboprophylaxis with rivaroxaban for 35 days when compared with no anticoagulation, resulted in better clinical outcomes, including a reduction in major and fatal thromboembolic events without increasing major bleeding.


June 2021 - ATAGI & THANZ COVID-19 Vaccine Statement

March 2021 - Message from our CEO

March 2021 - Symptoms of VTE after COVID-19 vaccination

April 2020 - COVID-19 and Thrombosis - International Society of Thrombosis and Haemostasis

March 2020 - Impact on blood transfusions and blood donations