FILE - In this Aug. 14, 2020, file photo, laboratory technicians work at the mAbxience biopharmaceutical company on an experimental coronavirus vaccine developed by Oxford University and the laboratory AstraZeneca in Garin, Argentina. AstraZeneca announced Monday, Aug. 31, its vaccine candidate has entered the final testing stage in the U.S. (AP Photo/Natacha Pisarenko, File)

AstraZeneca COVID-19 vaccine study paused after one illness

An AstraZeneca spokesperson confirmed the pause in vaccinations covers studies in the U.S. and other countries

Late-stage studies of AstraZeneca’s COVID-19 vaccine candidate are on temporary hold while the company investigates whether a recipient’s “potentially unexplained” illness is a side effect of the shot.

In a statement issued Tuesday evening, the company said its “standard review process triggered a pause to vaccination to allow review of safety data.”

AstraZeneca didn’t reveal any information about the possible side effect except to call it “a potentially unexplained illness.” The health news site STAT first reported the pause in testing, saying the possible side effect occurred in the United Kingdom.

An AstraZeneca spokesperson confirmed the pause in vaccinations covers studies in the U.S. and other countries. Late last month, AstraZeneca began recruiting 30,000 people in the U.S. for its largest study of the vaccine. It also is testing the vaccine, developed by Oxford University, in thousands of people in Britain, and in smaller studies in Brazil and South Africa.

Two other vaccines are in huge, final-stage tests in the United States, one made by Moderna Inc. and the other by Pfizer and Germany’s BioNTech. Those two vaccines work differently than AstraZeneca’s, and the studies already have recruited about two-thirds of the needed volunteers.

Temporary holds of large medical studies aren’t unusual, and investigating any serious or unexpected reaction is a mandatory part of safety testing. AstraZeneca pointed out that it’s possible the problem could be a coincidence; illnesses of all sorts could arise in studies of thousands of people.

“We are working to expedite the review of the single event to minimize any potential impact on the trial timeline,” the company statement said.

It’s likely the unexplained illness was serious enough to require hospitalization and not a mild side effect such as fever or muscle pain, said Deborah Fuller, a University of Washington researcher who is working on a different COVID-19 vaccine that has not yet started human testing.

“This is not something to be alarmed about,” Fuller said. Instead, it’s reassuring that the company is pausing the study to figure out what’s happening and carefully monitoring the health of study participants.

Dr. Ashish Jha of Brown University said via Twitter that the significance of the interruption was unclear but that he was “still optimistic” that an effective vaccine will be found in the coming months.

“But optimism isn’t evidence,” he wrote. “Let’s let science drive this process.”

Angela Rasmussen, a virologist at Columbia University in New York, tweeted that the illness may be unrelated to the vaccine, “but the important part is that this is why we do trials before rolling out a vaccine to the general public.”

During the third and final stage of testing, researchers look for any signs of possible side effects that may have gone undetected in earlier patient research. Because of their large size, the studies are considered the most important study phase for picking up less common side effects and establishing safety.

The trials also assess effectiveness by tracking who gets sick and who doesn’t between patients getting the vaccine and those receiving a dummy shot.

The development came the same day that AstraZeneca and eight other drugmakers issued an unusual pledge, vowing to uphold the highest ethical and scientific standards in developing their vaccines.

The announcement follows worries that President Donald Trump will pressure the U.S. Food and Drug Administration to approve a vaccine before it’s proven to be safe and effective.

The U.S. has invested billions of dollars in efforts to quickly develop multiple vaccines against COVID-19. But public fears that a vaccine is unsafe or ineffective could be disastrous, derailing the effort to vaccinate millions of Americans.

Representatives for the FDA did not immediately respond to requests for comment Tuesday evening.

AstraZeneca’s U.S.-traded shares fell more than 6% in after-hours trading following reports of the trial being paused.

___

Associated Press writers Matthew Perrone and Carla K. Johnson contributed to this report.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Lauran Neergaard, The Associated Press

Coronavirusvaccines

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

’Herbert’ Shane Hartman with his daughter Isla. (Shane Hartman Facebook photo)
Love for daughter and drumming leads to author’s first book

Shane Hartman spent very spare moment writing and illustrating Isla’s New Drum

“We have to make a call out to address this now so our people don’t have to feel fearful,” said Tribal Chief Mina Holmes. (Carrier Sekani Tribal Council Facebook photo)
Carrier Sekani Tribal Council seeks Indigenous-led task force in northern B.C. hospitals

Request made in an open letter to federal minister Carolyn Bennett

NDP headquarters on election night, Oct. 24, 2020. (Katya Slepian/Black Press Media)
ELECTION 2020: Live blog from B.C. party headquarters

BC NDP projected to win majority government – but celebrations will look different this election

B.C. Green Party leader Sonia Furstenau outlines her party's climate action platform at Nanaimo's Vancouver Island Conference Centre earlier this month. (News Bulletin file photo)
Green leader Furstenau declared victor in her home riding on Vancouver Island

Cowichan Valley voters elect freshly minted party leader for her second term

Submitted
BC VOTES 2020: John Rustad re-elected in Nechako Lakes riding

The result is based on preliminary vote count and the final results will be available after Nov.6

Provincial health officer Dr. Bonnie Henry updates the COVID-19 situation, B.C. legislature, Oct. 26, 2020. (B.C. government)
B.C.’s COVID-19 case count jumps by 287, another senior home outbreak

Two more deaths recorded, community outbreak in Okanagan

An untitled Emily Carr painting of Finlayson Point was donated to the Art Gallery of Greater Victoria by brothers Ian and Andrew Burchett. The painting had been in their family for several decades. (Courtesy of the Art Gallery of Greater Victoria)
Never before seen painting by famed B.C. artist Emily Carr gifted to Victoria gallery

Painting among several donated to Art Gallery of Greater Victoria

The B.C. Centre for Disease control is telling people to keep an eye out for the poisonous death cap mushroom, which thrives in fall weather conditions. (Paul Kroeger/BCCDC)
Highly poisonous death cap mushroom discovered in Comox

This marks first discovery on Vancouver Island outside Greater Victoria area

100 Mile Conservation officer Joel Kline gingerly holds an injured but very much alive bald eagle after extracting him from a motorist’s minivan. (Photo submitted)
Rescued bald eagle that came to life in B.C. man’s car had lead poisoning

Bird is on medication and recovering in rehab centre

Janet Austin, lieutenant governor of B.C., was presented with the first poppy of the Royal Canadian Legion’s 2020 Poppy Campaign on Wednesday. (Kendra Crighton/News Staff)
PHOTOS: B.C. Lieutenant Governor receives first poppy to kick off 2020 campaign

Janet Austin ‘honour and a privileged’ to receive the poppy

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Premier-elect John Horgan and cabinet ministers are sworn in for the first time at Government House in Victoria, July 18, 2017. (Arnold Lim/Black Press)
Pandemic payments have to wait for B.C. vote count, swearing-in

Small businesses advised to apply even if they don’t qualify

A raccoon paid a visit to a Toronto Tim Hortons on Oct. 22, 2020. (shecallsmedrew/Twitter)
Who are you calling a trash panda? Raccoon takes a shift at Toronto Tim Hortons

Tim Hortons said animal control was called as soon they saw the surprise visitor

The duffel bags were found to contain 84 pounds of cocaine, valued at approximately $1.2 million and 198 pounds of methamphetamine, valued at approximately $960,000. Photo courtesy U.S. Customs and Border Protection.
2 men accused of fleeing border agents near U.S.-B.C. border with $2M in drugs

Cocaine and methamphetamine seized by U.S. law enforcement in remote Idaho area near Canadian border

Most Read