New Delhi (NVI): A large, Phase 3 study testing of a highly-anticipated COVID-19 vaccine candidate being developed by AstraZeneca and the University of Oxford at dozens of sites has been put on hold due to a suspected serious adverse reaction in a participant in the United Kingdom.
The company is now investigating if a report of a patient with a serious side effect is linked to the shot.
The outcome of vaccine trials is being closely watched around the world.
Its move to Phase 3 testing in recent weeks has involved some 30,000 participants in the US as well as in the UK, Brazil and South Africa. Phase 3 trials in vaccines often involve thousands of participants and can last several years.
“As part of the ongoing randomized, controlled global trials of the Oxford coronavirus vaccine, our standard review process triggered a pause to vaccination to allow review of safety data. 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 in a statement.
“The company is working to expedite the review of the single event to minimize any potential impact on the trial timeline,” it added.
The nature of the safety issue and when it happened were not immediately known, although the participant is expected to recover, according to Stat News.
The report said suspension of the trial was having an impact on other AstraZeneca vaccine trials – as well as on clinical trials being conducted by other vaccine makers.
AstraZeneca only began its Phase 3 trial in the U.S. in late August. The U.S. trial is currently taking place at 62 sites across the country, according to clinicaltrials.gov, a government registry, though some have not yet started enrolling participants. Phase 2/3 trials were previously started in the U.K., Brazil, and South Africa.