AstraZeneca Says Cause of ‘Unexplained Illness’ in Phase 3 Vaccine Trial Hasn’t Been Confirmed

Reports “are incorrect” that a participant in AstraZeneca’s COVID-19 vaccine trial that was paused Tuesday suffered from transverse myelitis, an AstraZeneca spokesperson told FDAnews Wednesday.

The UK-based drugmaker voluntarily halted trials of AZD1222 on Tuesday because of a single “unexplained illness” that occurred in the UK trial. Vaccinations are currently on hold in order to assess the data (DID, Sept. 9).

The cause of the illness was reportedly based on comments by the company’s CEO Pascal Soriot. However, Soriot actually said that there is no final diagnosis and that there will not be one until more tests are carried out, the spokesperson said. The tests will be delivered to an independent safety monitoring committee that will review the event and establish a final diagnosis, the AstraZeneca spokesperson said.

“We can also confirm that there was a brief trial pause in July while a safety review took place after one volunteer was confirmed to have an undiagnosed case of multiple sclerosis, which the independent panel concluded was unrelated to the vaccine,” the spokesperson added.

The UK drugmaker explained in its Tuesday announcement of the trial freeze that it is simply following routine safety procedures, and there’s no confirmation yet that the serious adverse event was caused by the vaccine. The company said it is currently working to speed up its evaluation of the event “to minimize any potential impact on the trial timeline.”

It is not yet known if the analysis will delay the delivery of results from the phase 3 trial, which AZ has said it anticipates seeing later this year. — James Miessler