Two coronavirus vaccine trials are on the verge of restarting after pauses to monitor possible safety issues.
The Johnson & Johnson coronavirus vaccine trial, paused earlier this month due to an unexplained illness in a participant, will resume very soon. An independent committee investigated the case of a man in the trial who suffered a stroke and concluded it was not related to the vaccine, according to two individuals familiar with the trial who spoke on the condition of anonymity.
The AstraZeneca vaccine trial, on hold in the United States since early September, also got the greenlight to restart from the Food and Drug Administration, according to a company statement. Some of the AstraZeneca trials in the United States had been taking place at Indiana University School of Medicine in Indianapolis.
When a potential adverse event occurs during a clinical trial, the testing is typically stopped so that an independent data and safety monitoring board can thoroughly investigate and determine whether the problem was likely related to the vaccine. Rules around clinical trials and patient privacy usually restrict details of adverse events from being released, but the tremendous scrutiny of the coronavirus vaccine trials has led many experts to call for greater transparency in disclosing and explaining the reasons for trial pauses.
In the Johnson & Johnson trial, which was paused on Oct. 12, a man who received a vaccination suffered a stroke that may have been triggered by an infection.
To conclude it was not related to the shot, investigators probed not only the medical details of the event, but also examined a safety database of 100,000 people who have received vaccines that use the same underlying technology.
Johnson & Johnson spokesman Jake Sargent declined to comment.
The company is testing the only vaccine that aims to protect people with a single shot; other prospective vaccines require a return visit and second shot three to four weeks after the first to trigger a protective immune response. It was the second late-stage trial put on hold after the vaccine being developed by AstraZeneca and the University of Oxford was halted on Sept. 6 after a British participant developed a neurological problem. While the AstraZeneca study resumed in the rest of the world, it did not get clearance in the U.S. until Friday.
In the AstraZeneca trial, no further information was provided about the incident or why regulators in the U.S. kept the study on hold for so much longer than other countries.
“The restart of clinical trials across the world is great news as it allows us to continue our efforts to develop this vaccine to help defeat this terrible pandemic,” said AstraZeneca chief executive Pascal Soriot. “We should be reassured by the care taken by independent regulators to protect the public and ensure the vaccine is safe before it is approved for use.”