How UK doctor linked rare blood-clotting to AstraZeneca Covid jab

Prof Marie Scully developed a diagnostic test at University College London hospital after seeing rare side-effect in patient

• Coronavirus - latest updates
• See all our coronavirus coverage

Marie Scully was alarmed and puzzled. It didn't make sense," she said. The consultant haematologist at University College London hospital (UCLH) had seen patients with blood clots in the brain and low platelets before and, although it was unusual, she always knew why. But there was no reason for the condition of the young woman in her 30s she was treating in early March.

Now when you have blood clots in the brain like that there's always a cause, and it was difficult to pinpoint the cause," said Prof Scully. It didn't fit our normal diagnostic boxes, let's say. She was a young woman with cerebral venous sinus thrombosis, and she had a low platelet count."