The pharmaceutical company AstraZeneca paused its late-stage trials of Coronavirus vaccine due to a suspected adverse reaction in a participant.
One of the volunteers was diagnosed with with transverse myelitis, an inflammatory syndrome that affects the spinal cord and can be caused by viral infections. It is not yet determined whether the illness was caused by the vaccine or was coincidental.
The AstraZeneca-Oxford University vaccine is seen as a strong contender among dozens being developed around the world. It has been undergoing phase 3 of the trials, involving 30,000 participants in the US as well as in the UK, Brazil and South Africa.
Wellcome Trust director Sir Jeremy Farrar, an expert in infectious disease control, said there were often pauses in vaccine trials.
It was important any adverse reactions were taken seriously, he said.
And it underlined the importance of “independent oversight”.
“It is crucial that all that data is shared openly and transparently because the public must have absolute trust that these vaccines are safe and effective and, in the end, will hopefully bring the pandemic to a close,” Sir Jeremy added
It is only at the late-stage trials when rare side effects can be revealed, which in turn could undercut thousands of people on global scale.