AstraZeneca has “voluntarily paused” late-stage trials of the highly-anticipated COVID-19 vaccine it is developing with the University of Oxford after one of the study volunteers developed an unexplained illness, the company said on September 9, reports said.
The AstraZeneca-Oxford vaccine is seen as one of the most promising of the vaccines against coronavirus that are currently under development.
“As part of the ongoing randomized, controlled global trials of the Oxford coronavirus vaccine, our standard review process was triggered and we voluntarily paused vaccination to allow review of safety data by an independent committee,” said Michele Meixell, the company’s spokeswoman.
“This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials, while it is investigated, ensuring we maintain the integrity of the trials.”
AstraZeneca said that in large trials, illnesses would sometimes happen by chance but the issue had to be reviewed independently.
“We are working to expedite the review of the single event to minimise any potential impact on the trial timeline,” Meixell said.
The drug is in trials involving thousands of people in the United States, Brazil, South Africa and the UK where the patient fell ill.
Clinical holds are not uncommon, but AstraZeneca’s is the first phase-three COVID-19 vaccine trial known to have been put on hold. It is unclear how long the suspension might last and shares of the company fell more than six percent in after-hours trading on the New York Stock Exchange.
The progress of the company’s trial – and those of all COVID-19 vaccines in development – are being closely watched given the pressing need for new ways to curb the global pandemic. There are currently nine vaccine candidates in Phase III trials.
Separately, nine leading US and European vaccine developers have promised to uphold the scientific standards in the global race to contain the pandemic.
The companies, including Pfizer, GlaxoSmithKline and AstraZeneca, in a joint statement made a “historic pledge … to uphold the integrity of the scientific process as they work towards potential global regulatory filings and approvals of the first COVID-19 vaccines”.
The unusual move to promise to play by well-established rules underlines the highly politicised debate over what action is needed to rein in the spread of the disease.
The head of the Food and Drug Administration, the US regulator, said in August that the normal approval process could be bypassed for a COVID-19 vaccine if officials were convinced the benefits outweighed the risks. The comments prompted a call for caution from the World Health Organisation.
Developers globally have yet to produce large-scale trial data showing actual infections in participants, but Russia granted approval for a COVID-19 vaccine last month, prompting some Western experts to criticise a lack of testing.