Symptoms that prompted the University of Oxford and partner AstraZeneca Plc to pause trials evaluating their experimental coronavirus vaccine probably weren’t related to the shot itself, according to documents sent to participants.
Safety reviews were carried out when participants in the Oxford study developed unexplained neurological symptoms including limb weakness or changed sensation, a participant information sheet posted online by Oxford shows.
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 letter reads. In each of these cases, after considering the information, the independent reviewers recommended that vaccinations should continue.
Questions have surrounded a UK volunteer’s illness in the trial and the safety data that triggered the halt. The Oxford-AstraZeneca vaccine study remains on hold in the US pending a regulatory review, federal officials said.
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The interruption highlights the uncertainties researchers face on the road to developing a vaccine. Although temporary halts in such trials aren’t uncommon, the pause in the Oxford study has heightened worries about when the first shots providing protection against the pandemic could be ready.
AstraZeneca declined to comment. Oxford representatives couldn’t immediately be reached for comment.
Trials resumed in the UK over the weekend, while researchers in South Africa also restarted tests, saying that an independent safety committee concluded that the event was unlikely to be related to the vaccination.
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Close monitoring of the affected individuals and other participants will be continued, according to the document.
AstraZeneca Chief Executive Officer Pascal Soriot had previously said it wasn’t clear whether the participant had a condition called transverse myelitis, after news reports cited it as a suspected diagnosis.