Covid-19 vaccine trial halted after serious adverse reaction

Covid-19 vaccine trial halted after serious adverse reaction

AstraZeneca said Sept. 9 it has taken a "voluntary pause" of its phase 3 COVID-19 vaccine trial after an adverse reaction in a patient in the U.K. 

The drugmaker, which has been conducting its vaccine trials with the University of Oxford in England, said the delay is routine when there is a potentially unexplained illness in a trial. 

"In large clinical trials, illnesses will happen by chance and must be independently reviewed. AstraZeneca is working to expedite the review of the single event to minimize any potential impact on the trial timeline. We are committed to the safety of our participants and the highest standards of conduct in our trials," the drugmaker stated. 

The nature of the adverse reaction and when it happened is unclear, as is the length of the trial delay.

The adverse effect has also halted trials at the University of Kansas Medical Center and Children's Mercy, both in Kansas City, as well as at the University of Wisconsin Hospital in Madison.