Johnson & Johnson pauses large, late-stage COVID-19 vaccine trial after testing subject contracts unexplained illness

Johnson & Johnson announced on Monday that it immediately paused a large, late-stage clinical trial of its coronavirus vaccine after one of its volunteers fell ill with an unexplained sickness, according to CNN.

What are the details?

A statement from the company on Monday announced that the advanced clinical trial of the vaccine — which is being developed by Johnson & Johnson's vaccine arm, Janssen Pharmaceutical Companies — has been paused following a participant's illness.

"Following our guidelines, the participant's illness is being reviewed and evaluated by the ENSEMBLE independent Data Safety Monitoring Board (DSMB) as well as our internal clinical and safety physicians," the company said in a statement. "Adverse events — illnesses, accidents, etc. — even those that are serious, are an expected part of any clinical study, especially large studies."

The company did not specify the details of the unexplained illness.

"Based on our strong commitment to safety, all clinical studies conducted by the Janssen Pharmaceutical Companies of Johnson & Johnson have prespecified guidelines," the statement continued. "These ensure our studies may be paused if an unexpected serious adverse event (SAE) that might be related to a vaccine or study drug is reported, so there can be a careful review of all of the medical information before deciding whether to restart the study."

The company said that it will study the participant's illness while protecting the participant's privacy.

"It's important to have all the facts before we share additional information," the company's statement pointed out. "Serious adverse effects are not uncommon in clinical trials, and the number of serious adverse events can reasonably be expected to increase in trials involving large numbers of participants. Further, as many trials are placebo-controlled, it is not always immediately apparent whether a participant received a study treatment or a placebo."

'Actually a good thing that these companies are pausing these trials'

According to the New York Times, trial pauses are "often lifted quickly after the illness is investigated and deemed not to be a serious safety risk."

Dr. Phyllis Tien, an infectious disease expert at the University of California San Francisco, told the outlet, “It's actually a good thing that these companies are pausing these trials when these things come up. We just need to let the sponsor and the safety board do their review and let us know their findings."

Dr. Luciana Borio, who oversaw public health preparedness for the National Security Council under President Donald Trump, added, "It doesn't mean that the adverse event is related to the vaccine, but it needs to be investigated thoroughly."