Jonson & Johnson has paused its final stage clinical trials for a coronavirus candidate vaccine due to a patient's "unexplained illness."
"We have temporarily paused further dosing in all our COVID-19 vaccine candidate clinical trials, including the Phase 3 ENSEMBLE trial, due to an unexplained illness in a study participant," the company said in a statement Monday.
"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."
It said that adverse events such as illnesses and accidents are an "expected part of any clinical study, especially large studies."
"We must respect this participant’s privacy," it said, adding that additional information will be shared soon.
No details were given if the participant was part of the experimental vaccine group or in the placebo control (fake drug) one.
Johnson & Johnson's candidate vaccine is one of the four large-scale trials underway, with up to 60,000 participants, in the US and the second one halted so far.
AstraZeneca's trial with 30,000 people was paused early September after a second participant was diagnosed with a neurological condition.
Pharma giants have resisted the idea of taking a shortcut in rolling out a vaccine for the novel virus, despite pressure from President Donald Trump, who promised the antigen could be ready before the Nov. 3 presidential election.