Meanwhile, the US Food and Drug Administration has expanded its investigation of a serious illness into the AstraZeneca Plc Covid-19 vaccine study and will analyze data from previous trials of similar vaccines developed by the same scientists, three sources familiar with the details told Reuters. The large late-stage American trial of AstraZeneca has been on hold since Sept. 6, after a study participant in Britain fell ill with what was believed to be a rare spinal inflammatory disorder called transverse myelitis.
The expanded scope of the FDA investigation increases the likelihood of further delays for what has been one of the most advanced COVID-19 vaccine candidates in development. The requested data was expected to arrive this week, after which the FDA would need time to analyze it, two of the sources said.
Effective vaccines are considered essential to help end a pandemic that has killed more than a million people around the world.
The administration of President Donald Trump has pledged $ 1.2 billion to support the development of the AstraZeneca vaccine and secure 300 million doses for the United States. Other leading companies in the US vaccine race include Pfizer Inc, Moderna Inc and Johnson & Johnson.
Regulators in the UK, Brazil, India and South Africa have allowed AstraZeneca to resume its clinical trials there.
However, the FDA wants to determine whether similar side effects emerged in trials of other vaccines designed by AstraZeneca’s coronavirus vaccine partner, researchers at the University of Oxford, the sources said. That doesn’t mean the agency believes there were safety concerns associated with any of these vaccines, they added. “It just shows that the FDA is being thorough,” said one of the sources.
What further complicates the situation is that the data requested by the FDA is in a different format than that required by the US regulator, two of the sources said.
The FDA declined to comment on the discussions involving an experimental product. Oxford did not respond to requests for comment. AstraZeneca, in a statement, said: “We continue to work with the FDA to facilitate the review of the information necessary to make a decision regarding the resumption of the trial in the United States.”
All the vaccines you want to review use a modified adenovirus as a vector to safely transport genetic material from target diseases (flu, Middle East respiratory syndrome, and other diseases) to the body to stimulate an immune system response to fight future infections.
While other vaccine developers have used human adenoviruses for such vaccines, the Oxford researchers chose an adenovirus that is found in chimpanzees. They considered that this would reduce the likelihood of an individual’s immune system attacking the vector virus due to previous exposure rather than the intended target.
Reuters reviewed six research articles detailing the safety data of vaccines using the modified chimpanzee adenovirus called ChAdOx1 for diseases such as tuberculosis, prostate cancer and influenza.
In one of those trials, a serious adverse event cited by the investigators was considered not related to the vaccine.
The type of review the FDA is conducting generally aims to analyze the raw data for other side effects, the sources said.
The US government’s effort to accelerate the development of a COVID-19 vaccine, and Trump’s promises that it could be available before the November 3 presidential election, has raised concerns of political interference in the regulatory process. at the expense of security. The FDA has denied it.
AstraZeneca’s vaccine development could also be slowed by a change in its clinical trial protocols to show that it has met predetermined safety and efficacy standards.
Independent safety monitors will conduct their first vaccine safety and efficacy review after 75 trial subjects become infected with COVID-19, compared to the original initial review plan after approximately 40 infections, according to a Reuters review of protocol documents issued in July and amended. in mid-September.
Safety monitors may decide to stop the trial if the vaccine proves to be very effective and therefore should be considered for public use before the trial is concluded, or if serious safety concerns arise.
“Safety was likely a major reason” for the change, said Thomas Lumley, chair of biostatistics at the University of Auckland, who was not involved in the study.
AstraZeneca did not say why it had made the change to its protocol.
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