AstraZeneca should know before the end of the year whether its experimental vaccine can protect people from COVID-19 if trials that were paused after a participant became ill resume, chief executive Pascal Soriot said Thursday.
"If the review by the safety committee allowed us to restart the trial, I still think we are on track for having a set of data that we would submit before the end of the year," Soriot said at an online event hosted by Britain's Tortoise Media about the future of the world after the pandemic.
AstraZeneca is working with the U.K.'s University of Oxford on a coronavirus vaccine that had until recently shown promising results.
On Tuesday, officials announced that the trial would be put on hold after one study participant in the U.K. reportedly developed a spinal cord injury.
"What happened here is not uncommon," Soriot said. "The process is always in vaccine trials, that if you have an event that you didn't expect, that you stop to look at it and explore it and study it."
The specific condition the participant is suffering from is still unclear and being tested, Soriot said. He didn't provide further information about the individual affected.
A problem lies with the public's perception of the vaccine.
Some experts have criticized how the company announced the halt in the trials, saying it lacked transparency and could hurt public trust. Initially, AstraZeneca didn't disclose details of the adverse event to the public, but revealed more to investors during a private conference call Wednesday.
"I don't think they realize how damaging the way they're conveying information to the public is," Dr. Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine in Houston and co-director of the Center for Vaccine Development at Texas Children's Hospital, told NBC News. "There's an awful anti-vaccine movement out there and anti-science movement, and now it's globalizing."
Companies alongside trusted figures in health information should be front and center explaining and reassuring the public about any challenges in the trials, Hotez said.
"The public should not be afraid. I think these trials are being well done and they'll be conducted with lots of rigor," he said.
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Soriot acknowledged the public scrutiny of the trial.
"The difference with other vaccines trials is the whole world is not watching them," he said Thursday.
A definitive timeline of when the trial will resume has not been announced, and Soriot said that would be up to an independent safety committee.
Soriot also defended the company's communications strategy, saying it followed protocol by notifying regulators in all countries involved in the study first.
"You don't have to ... make a press announcement. That's not the process," he said.
AstraZeneca began its Phase 3 clinical trials in the U.S. last week. NBC News has confirmed that the pause has affected trial sites in the U.S.
Trials were also paused in Brazil, according to a statement from the Federal University of São Paulo, which is coordinating them in that country.
The Oxford trial was the third Phase 3 trial to begin in the U.S. Pfizer and Moderna began their Phase 3 trials in late July and have already enrolled about 30,000 volunteers.
The Oxford vaccine uses a type of virus called an adenovirus to teach the immune system how to make antibodies to attack the coronavirus' so-called spike protein. It's that spike protein that allows the virus to infect human cells.