Brazil reports that volunteer in Astrazeneca COVID vaccine trial died

What killed him/her

Brazil health authority Anvisa says a volunteer in the clinical trials of Astrazeneca/Oxford COVID-19 vaccine has died. The Brazil Federal University Of Sao Paulo says the volunteer was Brazilian.
Now, people die all the time and there are thousands of people doing virus trials so there’s a good chance it’s a coincidence. Brazil’s health authority said the trials will continue, so you can infer it might not be related.
Still, ADRs of AstraZeneca are quickly down almost $2 to $50.62.
Update: The University of Oxford said that it has carefully assessed the case in Brazil and there have been no concerns about the safety of the trial. Shares of AZN have pared nearly all the loss with a clearer message here that the death wasn’t believed to be related to the vaccine.
The bad news is that this is more fodder for the anti-vaxxers.