Because of the pandemic, USA health officials and drugmakers have been accelerating the development of vaccine candidates by investing in multiple stages of research even though doing so could be for naught if the vaccine ends up not being effective or safe.
The university said in large trials such as this "it is expected that some participants will become unwell and every case must be carefully evaluated to ensure careful assessment of safety".
On the anticipation for an effective Covid-19 vaccine, she said, "we have to remember that clinical trials take time, we can not rush them, because we have to collect enough data on enough numbers of people to satisfy ourselves and satisfy the regulatory agencies that a particular drug or vaccine is safe and having the effect that you want it to have".
South Korea aims to secure enough new coronavirus vaccines to administer to 30 million people, or roughly 60 percent of the country's population, the health ministry said Tuesday.
"Let me tell you something". Volunteers from some of the worst affected countries - Britain, Brazil, South Africa and the US - are taking part in the trial.
Coronavirus vaccine tracker: AstraZeneca's development process hits a snag after a participant shows signs of severe illness.
The details of the adverse reaction are still unclear but StatNews has reported the CEO of AstraZeneca said to investors privately the subject was experiencing neurological symptoms consistent with an inflammatory spinal condition called transverse myelitis. It too had "paused" clinical trials in India, albeit a day after AZ announced similar action globally.
"On 6 September, the standard review process triggered a voluntary pause to vaccination across all global trials to allow review of safety data by independent committees, and worldwide regulators", the company said, adding, "The UK committee has concluded its investigations and recommended to the MHRA that trials in the UK are safe to resume".
The university insisted that it was "committed to the safety of our participants and the highest standards of conduct in our studies and will continue to monitor safety closely". On Monday, it said it had enrolled more than 29,000 volunteers. However, doctors also say Covid-19 deaths are being underreported to avoid panic. The World Health Organization (WHO) had flagged AstraZeneca's as the most promising.
Italy's health minister, Roberto Speranza, welcomed the resumption of the vaccine trial, but warned that prudence was still necessary. "In the meantime, the key continues to be our behavior".