A volunteer in a clinical trial of the COVID-19 vaccine being developed by Astrazeneca and Oxford University has died in Brazil.
Brazil's health authority said on Wednesday that although the volunteer had died, the trial would continue.
So far 8,000 people have been given the first dose of the vaccine in six cities in Brazil, which is grappling with one of the world's worst outbreaks of the disease.
A source familiar with the matter told Reuters that the volunteer who had died was likely to have been part of a control group that did not receive the COVID-19 vaccine, suggesting that the volunteer was instead given a meningitis jab.
Oxford University confirmed that testing would continue, adding that after careful assessment: 'There have been no concerns about the safety of the clinical trial.'
But AstraZeneca declined to comment immediately.
This follows a pause in the trials of the vaccine last month when a patient in the UK fell ill. The trial resumed days later but is still on hold in the U.S.
Also on Wednesday, Brazil's President said their federal government would not buy the vaccine from China's Sinovac, contradicting what his health minister said the day before, that it would be included in the nation's immunization program.
Brazil has the second deadliest outbreak of the coronavirus, after the United States, with more than 154-thousand people killed.