AstraZeneca pauses COVID vaccine trial as pandemic deaths near 900,000

COVID vaccine vial and syringe
COVID vaccine vial and syringe

Tomasz Banaczek / iStock

Following media reports yesterday, AstraZeneca today confirmed it has voluntarily paused phase 3 trials of the COVID-19 vaccine developed with Oxford University so that an independent committee can investigate an unexplained illness in a UK participant.

In other global COVID-19 developments, the world neared the grim milestone of 900,000 deaths. So far, pandemic cases have reached 27,683,499, and 899,808 people have died from their infections, according to the Johns Hopkins online dashboard.

Experts says vaccine pause not surprising

AstraZeneca said the pause and investigation are standard whenever there is an unexplained illness, which can happen by chance in large clinical trials. It said it is working to expedite the view to minimize impact on the study timeline and that it is committed to participant safety and the highest safety standards for its trials.

Stat today, in an exclusive report based information shared from an AstraZeneca call with investors, said the case that triggered the pause involves a UK woman — who received the vaccine rather than placebo — has symptoms consistent with transverse myelitis whose diagnosis hasn't yet been confirmed, but whose condition is improving.

The company also revealed on the call that the trial had been paused once before in July when a participant had neurologic symptoms, which were later linked to multiple sclerosis and not the vaccine.

The Coalition for Epidemic Preparedness (CEPI), which is supporting two COVID-19 vaccine candidates, including AstraZeneca's, today commended the company and its collaborators at Oxford University for their transparency and for moving quickly to investigate the event and said a pause to explore a potential adverse reaction isn't unusual in the course of developing a new vaccine.

"Determining conclusively that vaccines are safe and effective is why it is so critical to perform well-designed randomised clinical trials," CEPI said on Twitter.

The vaccine (AZD1222) uses a nonreplicating chimpanzee adenovirus to deliver a SARS-CoV-2 spike protein to prompt an immune response. US government agencies including the National Institute for Allergy and Infectious Diseases are also supporting the vaccine, and the phase 3 trial is part of the US government's Operation Warp Speed effort to accelerate the development of COVID-19 countermeasures. Study participants are receiving two doses of vaccine or placebo given about 4 weeks apart and will be followed for 2 years after receiving their last dose. An independent Data Safety Monitoring Board is overseeing study safety and ethics.

At a Senate hearing on vaccines today, National Institutes of Health (NIH) Director Francis Collins, MD, PhD, said the study hold based on illness in one participant is reassuring and shows that there are no compromises on safety in the development of the vaccine.

In 2014 during early safety testing of the VSV-EBOV vaccine, Swiss researchers temporarily paused a trial after some participants in one of the study countries reported mild joint pain. The Ebola vaccine has since been approved by the European Commission and the US Food and Drug Administration and has been prequalified by the World Health Organization. It was found to be highly effective in phase 3 studies in West Africa's outbreak and has now been deployed three Ebola outbreaks in the Democratic Republic of Congo.

Deaths approach 900,000

As the pandemic's death count nears 900,000, three countries in the Americas are in the top five countries in fatalities: the United States, Brazil, and Mexico. Deaths are rising rapidly in India, which is currently the world's greatest hot spot and reported 95,529 cases and 1,168 deaths today.

Among other COVID-19 international headlines:

  • In the UK, Prime Minister Boris Johnson announced that amid a steep rise in COVID-19 cases, the country starting on September 14 will limit most gatherings to 6 people, down from 30 currently. However, according to a BBC report, the rules won't apply to schools, workplaces, COVID-secure weddings, funerals, and organized sports.

  • Greece's largest migrant camp, located on the island of Lesbos, was nearly destroyed by fire. The Moria camp is home to 12,000 people and recently reported its first COVID-19 cases. According to Reuters, 35 people have tested positive, and the camp had recently been placed on quarantine. Initial reports said fires broke out in several locations after officials attempted to isolate people who tested positive for the virus.

  • The Czech Republic ordered people wear face masks inside buildings starting tomorrow as daily cases rose above 1,000 for the first time, and Slovenia today reports a record daily high of 79 new cases, part of a spike that could result from more testing and the start of schools.

This week's top reads