The adverse events that led to a pause in trials evaluating AstraZeneca Plc’s Covid-19 vaccine candidate may not have been associated with the vaccine itself, according to a document outlining participant information that was posted online by the Oxford University.
Enrollment in the British drugmaker’s global trials of the vaccine, which it is developing with researchers at Oxford University, was paused on September 6, after a participant in its UK trial had a serious side effect thought to be a rare spinal inflammatory disorder called transverse myelitis.
Safety reviews were conducted when volunteers in the trials for testing the vaccine candidate, called AZD1222 or ChAdOx1 nCoV-19, developed unexplained neurological symptoms including changed sensation or limb weakness, and the study was paused while a safety review took place, according to the document.
“After independent review, these illnesses were either considered unlikely to be associated with the vaccine or there was insufficient evidence to say for certain that the illnesses were or were not related to the vaccine,” the document said.
The vaccine trials have resumed in Britain, Brazil and South Africa, but not yet in the United States.
AstraZeneca and Oxford University did not immediately respond to Reuters requests for comment.