A candidate who volunteered for the AstraZeneca-Oxford COVID-19 vaccine trial in Brazil died, stated Anvisa, Brazil's National Health Agency on Wednesday. While AstraZeneca did not comment on the individual issue, Oxford and other health agencies told news agencies Reuters and CNN that the trials will continue as there were no safety concerns surrounding the vaccine suggesting that the death was not linked to the vaccine.
It is not clear whether the participant received the placebo or the Oxford vaccine. As these trials are double blind trials, neither the participants nor the doctors conducting the trial are aware about what the participant has received. Labelled vials are sent to the vaccine trial sites. Only the original researchers who label the vials know whether it contains the vaccine or a placebo. In the current trial, half of the participants are receiving the experimental vaccine, the other half is receiving an already licensed vaccine for meningitis.
Review committees set in place by all the participating agencies which are AstraZeneca, Oxford, Anvisa, the Federal University of Sao Paulo which is coordinating phase three clinical trials, and Instituto D'Or, a medical research facility which served as a local partner for the study stated that no safety issues have been reported against the vaccine.
Anvisa did not provide further details about the candidate citing medical confidentiality protocols. Brazilian newspaper O Globo, however, reported that the candidate was a 28-year-old doctor who lived in Rio de Janeiro and had died due to COVID-19 complications. This information has not been publicly confirmed, yet.
An AstraZeneca spokesperson told New York Times that he would not comment on the particular case but added that all the due reviews had been followed. "These assessments have not led to any concerns about continuation of the ongoing study," he said.
Anvisa, also stated that an international safety board monitoring the vaccine study informed the agency about the death on October 19. Gustavo Mendes, a manager at Anvisa, told New York Times that the agency decided along with its United Kingdom counterpart not to halt the study because an assessment by the independent safety board overseeing it showed the volunteer's death was not related to the vaccine. Over 8,000 people are participating in the phase three clinical trials in Brazil. Brazil has the second highest number of COVID-19 deaths and with over 5.2 million cases has the third highest number of cases.
Oxford also confirmed to Reuters that it would continue the vaccine trials as "after careful assessment there have been no concerns about safety of the clinical trial." It also stated that "all significant medical incidents, whether participants are in the control group or the Covid-19 vaccine group, are independently reviewed."
BOOM spoke to Dr. Shahid Jameel, noted virologist and epidemiologist to understand why the trials would continue. "My understanding is that the person who died did not receive the experimental vaccine but was in the control arm. When thousands of people are involved in a phase three trial, people do die from natural causes. The important thing is that the Brazilian regulator was informed who reviewed the situation and allowed the trials to continue," Jameel said.
Vaccine Trials Halted Earlier
As the trials are being continued, even after a death, health experts believe that this could be because the candidate was not given the COVID-19 vaccine. When a participant in UK developed negative side effects after being administered the vaccine, the AstraZeneca trials were immediately halted across the world on September 6 and 7. After due deliberation, the vaccine trials were resumed in the UK on September 12 and subsequently in Brazil, India, and South Africa. The trials were set to resume in US, reported Reuters on October 20. It is not clear whether they have resumed.
Along with AstraZeneca, other COVID-19 vaccine trials have also been halted across the world due to arising complications. Johnson and Johnson stopped the phase three trials of its vaccine candidate on October 12 after a participant developed an illness. The Phase 3 trial of its vaccine began last month, with a goal of enrolling up to 60,000 volunteers across more than 200 sites in the United States and around the world.
(This story has been updated with Dr. Jameel's quote)