April 15, 2021

what is the risk of CVT following COVID-19, and how it compares to the risk with vaccines

We now know that Cerebral venous thrombosis (CVT) has been reported to occur in about 5 in a million people after first dose of the AZ-Oxford COVID-19 vaccine. But a key question was unknown: what is the risk of CVT following a diagnosis of COVID-19? We might expect this to be increased because COVID-19 is associated with other clotting disorders like stroke and brain haemorrhage.

New research from the University of Oxford has addressed this question using the TriNetX electronic health records network, recently used to show the neurological and psychiatric consequences of COVID-19 published at the SMC last week.

The researchers, led by Professor Paul Harrison and Dr Maxime Taquet from the Department of Psychiatry, counted the number of CVT cases diagnosed in the two weeks after a diagnosis of COVID-19 or after the first dose of vaccine.

Please note this data is a preprint, so it is early work that has not yet been through peer-review and is not published in a journal.

Journalists joined this SMC briefing to find out the answer they got.

Speakers included:

Prof Paul Harrison, Professor of Psychiatry, University of Oxford

Dr Max Taquet, NIHR Academic Clinical Fellow in Psychiatry, University of Oxford

Prof Masud Husain, Professor of Neurology & Cognitive Neuroscience, University of Oxford

Prof John Geddes, Head of Department of Psychiatry, University of Oxford, and Director of NIHR Oxford Health BRC

This Briefing was accompanied by an SMC Roundup of Comments.