WASHINGTON (WKOW) -- The National Institutes of Health director revealed to a Senate committee Wednesday, AstraZeneca's phase three trial of its COVID-19 vaccine is on hold because of a spinal cord issue in a female volunteer.
There is no final diagnosis for what the woman's complications are, but her condition is reportedly improving as more tests are being carried out.
"To have a clinical hold as has been placed on AstraZeneca as of yesterday because of a single serious adverse event is not at all unprecedented. This certainly happens in any large scale trial where you have tens of thousands of people invested in taking part and some of them may get ill. And you always have to try to figure out is that because of the vaccine or were they going to get that illness anyway?" said Dr. Francis Collins, the director of National Institutes of Health.
"When we say we are going to focus first on safety and make no compromises, here is exhibit A," added Collins.
The board overseeing the trial confirmed the woman was injected with the vaccine, not the placebo.
Even when a vaccine is approved, experts think it's going to take time.
"For wide availability, I'd say we're going to be well into 2021 when that happens if everything goes perfect in phase 3 clinical trials," said Dr. Amesh Adalja, an infectious disease specialist.
AstraZeneca said it's "working to expedite the review of the single event to minimize any potential impact on the trial timeline."
This vaccine is one of the three coronavirus vaccines in late-stage, phase three trials in the U.S.