COLUMBUS, Ohio (WCMH) – Trials for a potential COVID-19 vaccine were put on hold at the Ohio State Wexner Medical Center and worldwide after a participant came down with an unexplained illness. Pharmaceutical company AstraZeneca announced the voluntary pause while it investigates whether the illness could be an adverse side effect of the vaccine or a coincidence.

In early September, the Ohio State Wexner Medical Center announced it was recruiting 500 volunteers for the trial. It was one of numerous institutions selected to administer the vaccine developed by Oxford University and the British-Swedish company to 30,000 Americans, thousands in Europe and others in South America. The trials would involve shots, blood work and testing over a two-year period.

The OSU Wexner Medical Center said Wednesday it had not yet started the trial and was awaiting guidance from AstraZeneca. A UK participant in a later stage of the trial came down with the unexplained illness. AstraZeneca did not elaborate on the person’s symptoms or condition.

The company released the following statement to NBC4:

“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. 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. In large trials illnesses will happen by chance but must be independently reviewed to check this carefully. We are 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.”

Students at the Ohio State University were weighing the pros and cons of receiving a COVID-19 vaccine in its early stages of development and testing.

Paige Jones said she’d be willing to participate in the trial, even with potential risks.

“I just want to be a part of helping change this and get rid of this and help move on from this,” the college junior said. 

Sophomore Akshi Devanathan added, “If they’re successful, they can quickly distribute it to every single state and make sure people can get it as quickly as possible.”

Others were unsure about trusting a new vaccine.

“I would hold off just to see what the results are,” said sophomore Matthew Steigauf.

The AstraZeneca COVID-19 vaccine is one of several undergoing rapid trials in the U.S. as part of “Operation Warp Speed” (OWS). As its name suggests, the plan from the Department of Health and Human Services partners private firms and other federal agencies to accelerate the development of COVID-19 counter measures. It aims to deliver 300 million doses of a safe, effective vaccine to Americans by January 2021.

AstraZeneca could not clarify how long the hold will be on the trial.