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)

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

Tim Sutherland Sr. likes to go down to Harbour Quay and feel the breeze on his face. On stormy days when the wind whips the rain into his face, he thinks of his son Tim Sutherland Jr., and wonders whether he is warm and dry. (SUSAN QUINN/ Alberni Valley News)
Finding shelter from the storm

Search for housing a journey of false hope for Alberni father and adult son

Volunteers decorate the Alberni Valley Hospice Society on Saturday, Nov. 28. (ELENA RARDON / ALBERNI VALLEY NEWS)
Alberni Valley Hospice Society lights up for holidays

New event is a fundraiser for society that runs Ty Watson House hospice and other programs

A sign at the entrance to Ty-Histanis asks visitors to stay out of the community during the COVID-19 pandemic. (Andrew Bailey photo)
Nuu-chah-nulth nations on Vancouver Island hit hard by COVID-19

Seven nations dealing with positive tests, hospitalizations and death

Tseshaht Market is located on Highway 4 west of Port Alberni. (GOOGLE MAPS)
Tseshaht First Nation condemns actions of abusive customer

Customer objected to Tseshaht Market’s COVID-19 protection policy

A lightning strike destroyed a radio repeater on Porter Mountain, shutting down the Ministry of Transportation and infrastructure’s highway cam at Sutton Pass. (BC Transportation and Infrastructure photo)
Lightning strike shuts down camera on Tofino-Ucluelet highway

“One of our radio repeater sites was recently struck by lightning.”

A tongue-in-cheek message about wearing a face mask to curb the spread of COVID-19 on a sign outside a church near Royal Columbia Hospital, in New Westminster, B.C., on Sunday, Nov. 29, 2020. THE CANADIAN PRESS/Darryl Dyck
B.C.’s COVID-19 infection count climbs back up to 656

20 more people in hospital, active cases still rising

Dave Wallace coached the Parksville Royals for 23 years. (PQB News file photo)
B.C. baseball community mourns death of legendary Vancouver Island coach Dave Wallace

‘All who knew Dave and his passion for the game will miss him greatly’

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

THE CANADIAN PRESS/Nathan Denette
B.C. researchers launch study to test kids, young adults for COVID-19 antibodies

Kids and youth can often be asymptomatic carriers of the novel coronavirus

A sign is seen this past summer outside the Yunesit’in Government office west of Williams Lake reminding visitors and members to stay safe amid the COVID-19 pandemic. (Rebecca Dyok photo)
B.C. First Nation leaders await privacy commissioner decision on COVID-19 information

Release of life-saving data cannot wait, says coalition of First Nations

MLA Jennifer Whiteside is B.C.’s new minister of education. She is speaking out against Chilliwack school trustee Barry Neufeld and asking him to resign. (Black Press)
New education minister calls on Chilliwack trustee to resign

Whiteside echoes former minister’s promise to look at options to remove Barry Neufeld

Peter Beckett. ~ File photo
Supreme Court of Canada to decide if it will hear appeal in 2010 wife murder trial

Peter Beckett has stood trial twice for murder in connection with the death of his wife, Laura Letts-Beckett

Most Read