A volunteer taking part in the clinical trials of a promising Covid-19 vaccine has died in Brazil, leading to a number of alarmist headlines and speculation on social media. 

Oxford University is in advanced stages of testing an immunisation being developed with AstraZeneca, with volunteers in countries including Brazil, the UK and the US. Scientists have emphasised there is no cause for concern. 

The cause 

Most importantly, the volunteer is not thought to have received the vaccine and may have been given a placebo. 

The trial would have been suspended had the volunteer been given the vaccine, suggesting the person was part of the control group that was given a meningitis jab, a source familiar with the matter told Reuters.

AstraZeneca said it could not comment on individual cases due to patient confidentiality, but said all due processes had been followed and there were no issues with the trial continuing.

“Without details it’s impossible to know what has happened in this case but as the trial is continuing, I think we can assume the circumstances of the death were such that it was clearly not vaccine related,” Ian Jones, Professor of Virology at the University of Reading, said in a statement issued by independent science publicity group the Science Media Centre.

The volunteer

The identity of the person who died has not been confirmed by those running the trial but CNN Brasil reported he was a 28-year-old man who lived in Rio de Janeiro and died from Covid-19 complications.

Andrew Freedman, reader in Infectious Diseases and Honorary Consultant Physician at the Cardiff University School of Medicine, said: “Fortunately, deaths resulting from the administration of a trial drug or vaccine are very rare and would normally lead to the immediate discontinuation of the trial.”

The trial

The trial is continuing.

So far, 8,000 of the planned 10,000 volunteers in the trial have been recruited and given the first dose in six cities in Brazil, and many have already received the second shot, said a university spokesman.

Oxford said in a statement: “All significant medical incidents, whether participants are in the control group or the Covid-19 vaccine group, are independently reviewed.

“Following careful assessment of this case in Brazil, there have been no concerns about safety of the clinical trial and the independent review in addition to the Brazilian regulator have recommended that the trial should continue.”