The Brazil National Health Surveillance Agency said that a volunteer in AstraZeneca's COVID-19 vaccine trial has died. The patient was not identified, but according to the New York Post, he was a 28-year-old doctor who had been on the frontlines of the coronavirus pandemic.

It is unknown if he received the vaccine or a placebo.

A spokesperson from the University of Oxford, which is developing the vaccine with AstraZeneca, said that after reviewing the case, they have "no concerns about the safety of the clinical trial."

"The independent review in addition to the Brazilian regulator have recommended that the trial should continue," Oxford spokesperson Alexander Buxton said.

AstraZeneca's phase 3 clinical trials were put on hold in September after a participant in the United Kingdom developed a rare spinal inflammatory disorder. While the trials have since resumed in the U.K. and other countries, the company is still waiting for approval from U.S. regulators.

U.K. health officials found "insufficient evidence to say for certain" that the vaccine caused the patient to develop the disorder.

According to Reuters, that approval could come in the next few days. Sources who were briefed on the matter said the Food and Drug Administration has completed its review of the case but did not say how the agency plans to characterize the illness.

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