Mary Wilson
New member
15 APR 2021
Researchers at the University of Oxford have today reported that the risk of the rare blood clotting known as cerebral venous thrombosis (CVT) following COVID-19 infection is around 100 times greater than normal, several times higher than it is post-vaccination or following influenza.
The study authors, led by Professor Paul Harrison and Dr Maxime Taquet from Oxford University?s Department of Psychiatry and the NIHR Oxford Health Biomedical Research Centre, counted the number of CVT cases diagnosed in the two weeks following diagnosis of COVID-19, or after the first dose of a vaccine. The then compared these to calculated incidences of CVT following influenza, and the background level in the general population.
They report that CVT is more common after COVID-19 than in any of the comparison groups, with 30% of these cases occurring in the under 30s. Compared to the current COVID-19 vaccines, this risk is between 8-10 times higher, and compared to the baseline, approximately 100 times higher. ...
https://www.ox.ac.uk/news/2021-04-15...id-19-vaccines
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Cerebral venous thrombosis: a retrospective cohort study of 513,284 confirmed COVID-19 cases and a comparison with 489,871 people receiving a COVID-19 mRNA vaccine
Maxime Taquet,1,2, Masud Husain,3,4, John R Geddes,1,2, Sierra Luciano,5, Paul J Harrison1,2,
Abstract
Using an electronic health records network we estimated the absolute incidence of cerebral venous thrombosis (CVT) in the two weeks following COVID-19 diagnosis (N=513,284), or influenza (N=172,742), or receipt of the BNT162b2 or mRNA-1273 COVID-19 vaccines (N=489,871). The incidence of portal vein thrombosis (PVT) was also assessed in these groups, as well as the baseline CVT incidence over a two-week period. The incidence of CVT after COVID-19 diagnosis was 39.0 per
million people (95% CI, 25.2?60.2). This was higher than the CVT incidence after influenza (0.0 per million people, 95% CI 0.0?22.2, adjusted RR=6.73, P=.003) or after receiving BNT162b2 or mRNA-1273 vaccine (4.1 per million people, 95% CI 1.1?4.9, adjusted RR=6.36, P<.001). The relative risks were similar if a broader definition of CVT was used. For PVT, the incidence was 436.4 per million people (382.9-497.4) after COVID-19, 98.4 (61.4-157.6) after influenza, and 44.9 (29.7-68.0) after BNT162b2 or mRNA-1273. The incidence of CVT following COVID-19 was higher than the incidence observed across the entire health records network (0.41 per million people over any 2-week period).
Laboratory test results, available in a subset of the COVID-19 patients, provide preliminary evidence suggestive of raised D-dimer, lowered fibrinogen, and an increased rate of thrombocytopenia in the CVT and PVT groups. Mortality was 20% and 18.8% respectively. These data show that the incidence of CVT is significantly increased after COVID-19, and greater than that observed with BNT162b2 and mRNA-1273 COVID-19 vaccines. The risk of CVT following COVID-19 is also higher than the latest estimate from the European Medicines Agency for the incidence associated with ChAdO x1 nCoV-19 vaccine (5.0 per million people, 95% CI 4.3?5.8). Although requiring replication and corroboration, the present data highlight the risk of serious thrombotic events in COVID-19, and can help contextualize the risks and benefits of vaccination in this regard.
https://osf.io/a9jdq/
Researchers at the University of Oxford have today reported that the risk of the rare blood clotting known as cerebral venous thrombosis (CVT) following COVID-19 infection is around 100 times greater than normal, several times higher than it is post-vaccination or following influenza.
The study authors, led by Professor Paul Harrison and Dr Maxime Taquet from Oxford University?s Department of Psychiatry and the NIHR Oxford Health Biomedical Research Centre, counted the number of CVT cases diagnosed in the two weeks following diagnosis of COVID-19, or after the first dose of a vaccine. The then compared these to calculated incidences of CVT following influenza, and the background level in the general population.
They report that CVT is more common after COVID-19 than in any of the comparison groups, with 30% of these cases occurring in the under 30s. Compared to the current COVID-19 vaccines, this risk is between 8-10 times higher, and compared to the baseline, approximately 100 times higher. ...
https://www.ox.ac.uk/news/2021-04-15...id-19-vaccines
__________________________________________________ ___________________________
Cerebral venous thrombosis: a retrospective cohort study of 513,284 confirmed COVID-19 cases and a comparison with 489,871 people receiving a COVID-19 mRNA vaccine
Maxime Taquet,1,2, Masud Husain,3,4, John R Geddes,1,2, Sierra Luciano,5, Paul J Harrison1,2,
Abstract
Using an electronic health records network we estimated the absolute incidence of cerebral venous thrombosis (CVT) in the two weeks following COVID-19 diagnosis (N=513,284), or influenza (N=172,742), or receipt of the BNT162b2 or mRNA-1273 COVID-19 vaccines (N=489,871). The incidence of portal vein thrombosis (PVT) was also assessed in these groups, as well as the baseline CVT incidence over a two-week period. The incidence of CVT after COVID-19 diagnosis was 39.0 per
million people (95% CI, 25.2?60.2). This was higher than the CVT incidence after influenza (0.0 per million people, 95% CI 0.0?22.2, adjusted RR=6.73, P=.003) or after receiving BNT162b2 or mRNA-1273 vaccine (4.1 per million people, 95% CI 1.1?4.9, adjusted RR=6.36, P<.001). The relative risks were similar if a broader definition of CVT was used. For PVT, the incidence was 436.4 per million people (382.9-497.4) after COVID-19, 98.4 (61.4-157.6) after influenza, and 44.9 (29.7-68.0) after BNT162b2 or mRNA-1273. The incidence of CVT following COVID-19 was higher than the incidence observed across the entire health records network (0.41 per million people over any 2-week period).
Laboratory test results, available in a subset of the COVID-19 patients, provide preliminary evidence suggestive of raised D-dimer, lowered fibrinogen, and an increased rate of thrombocytopenia in the CVT and PVT groups. Mortality was 20% and 18.8% respectively. These data show that the incidence of CVT is significantly increased after COVID-19, and greater than that observed with BNT162b2 and mRNA-1273 COVID-19 vaccines. The risk of CVT following COVID-19 is also higher than the latest estimate from the European Medicines Agency for the incidence associated with ChAdO x1 nCoV-19 vaccine (5.0 per million people, 95% CI 4.3?5.8). Although requiring replication and corroboration, the present data highlight the risk of serious thrombotic events in COVID-19, and can help contextualize the risks and benefits of vaccination in this regard.
https://osf.io/a9jdq/