Trials of the Oxford University and AstraZeneca Covid vaccine were to resume in the United States as early as this week after it was suspended when a participant became ill. AstraZeneca's large, late-stage US trial has been on hold since September 6, after a participant in the company's UK trial fell ill with what was suspected to be a rare spinal inflammatory disorder called transverse myelitis. Four sources, who were briefed on the matter but asked to remain anonymous, told Reuters they have been told the trial could resume later this week after the US Food and Drug Administration completed its review. It was unclear how the FDA would characterise the illness, they said. An FDA spokeswoman declined to comment. The agency is requiring researchers conducting the trial to add information about the incident to consent forms signed by study participants, according to one of the sources.