AstraZeneca COVID-19 Vaccine Trial in Brazil Reports One Participant Death; Study Continues Uninterrupted

Compiled by Fan Dongdong

Recently, according to foreign media reports, a participant death occurred in AstraZeneca's global Phase III COVID-19 vaccine trial. Affected by this news, AstraZeneca's stock price experienced a slight decline.

Details regarding the death of one volunteer in this COVID-19 vaccine trial are relatively scarce. According to a report by CNBC, the deceased patient was Brazilian. However, it remains unclear whether AstraZeneca’s COVID-19 vaccine, AZD1222, was the cause of death. Despite this fatality, the Phase III trial in Brazil is currently set to continue.

Neither AstraZeneca nor its vaccine trial research partner, the University of Oxford, commented on the news of the death. CNBC reported that an AstraZeneca spokesperson stated that this approach was in line with “medical confidentiality and clinical trial regulations.” The spokesperson further stated that “significant medical events occurring during the trial will be carefully evaluated by the trial investigators,” adding that “based on current assessments, there are no concerns regarding the ongoing study.”

It is worth noting that the University of Oxford appears to share the same view. A spokesperson for the University of Oxford also told CNBC that, after evaluating the death cases in Brazil, there were “no concerns regarding the safety of the ongoing vaccine clinical trials.” Alexander Buxton, a spokesperson for the University of Oxford, told CNBC, “In addition to the Brazilian regulatory authorities, independent review bodies have also recommended that the vaccine trials should continue.”

As of now, the global COVID-19 pandemic continues to spread, with the United States and India ranking as the top two countries in terms of total infections. Brazil ranks third worldwide in reported COVID-19 cases. According to relevant statistics from Johns Hopkins University, the Brazilian government has reported over 5.2 million confirmed infections, with a total of 154,837 deaths.

Within hours of the news breaking that a patient had died in the Brazilian trial, other media outlets reported that the U.S. Food and Drug Administration (FDA) might decide to cancel AstraZeneca’s ongoing Phase III COVID-19 vaccine study in the United States. The trial had been on hold in the U.S. since September, following reports that a participant in the United Kingdom who received the candidate vaccine AZD1222 developed transverse myelitis, a severe inflammatory condition of the spinal cord. However, the female patient did not die; she was discharged and returned home after receiving hospital treatment. After a brief investigation and assessment of the incident, the UK Medicines and Healthcare products Regulatory Agency (MHRA) determined that there was insufficient evidence to prove that the condition was directly caused by the vaccine, and subsequently allowed the trial to resume in the United Kingdom.

AstraZeneca’s COVID-19 candidate vaccine, AZD1222, is a weakened adenovirus-based viral vector developed by the University of Oxford’s Jenner Institute in collaboration with the Oxford Vaccine Group. It utilizes a viral vector derived from a weakened version of an adenovirus, loaded with the genetic material encoding the SARS-CoV-2 spike protein. Following vaccination, the surface spike protein is produced, which primes the immune system to mount a response if the patient is subsequently infected with the novel coronavirus. In July, the company announced positive Phase I trial data, demonstrating that AZD1222 elicited both neutralizing antibodies and T-cell responses against the virus causing COVID-19.

Meanwhile, AstraZeneca is also conducting AZD1222 vaccine trials in India and South Africa. If the vaccine ultimately passes regulatory review and enters smooth production, AstraZeneca plans to manufacture up to 2 billion doses, with an estimated 400 million doses allocated for use in the United States and the United Kingdom, and 1 billion doses designated for low- and middle-income countries.

Reference Source: AstraZeneca Shares Drop Following Report of a COVID-19 Vaccine Study Patient Death in Brazil