Trials For AstraZeneca's Coronavirus Vaccine On Hold Due To Safety Issues

AstraZeneca has announced a temporary halt in the late-stage trials of its coronavirus vaccine. The announcement came after a volunteer from the U.K. started having an “unexplained illness” after receiving the shot.

AstraZeneca is developing the experimental COVID-19 vaccine with the University of Oxford. The vaccine is one of the most promising vaccines currently in development, with trials involving thousands of people in the U.S., Brazil, South Africa, and the U.K. underway.

In a statement, AstraZeneca spokeswoman Michele Meixell said the company had to temporarily pause the trials due to safety concerns. “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,” she said.

Meixell said such a safety protocol for large-scale trials is triggered when a volunteer experiences a serious adverse reaction from the drug being tested. “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,” she explained.

The company also explained that while illnesses normally happen in large trials, an independent review of such events is required. AstraZeneca is already working to speed up the review of the recent event to minimize any potential impact it might have on the trial timeline.

An expert from Georgetown University also said such a pause was “part of the process” of drug development. “For a pause the event would need to be serious; something related to the heart, lungs, kidneys, or other parts of the body’s health system that required medical attention and was sufficiently serious to merit a pause to this very important vaccine trial in order to make sure it is safe, and that the adverse effect is not due to the vaccine itself,” said Julie Fischer of the Center for Global Health Science and Security at Georgetown University.

Nine potential coronavirus vaccines are currently in late-stage trials and the trial for AstraZeneca’s COVID-19 vaccine was the first to be put on hold.