Johnson & Johnson announced Monday (October 12) it's temporarily paused trials for a COVID-19 vaccine after a participant in the study fell ill for unknown reasons.
The news delays one of the highest profile efforts to contain the global pandemic.
And also another major setback in the race for a COVID-19 vaccine, after AstraZeneca paused late-stage trials of its vaccine candidate last month, also due to unexplained illness in a trial participant.
Johnson and Johnson said in a statement that their participant's illness is being reviewed and evaluated by an independent monitoring board as well as the company's clinical and safety physicians.
The company said that the current "study pause" in giving doses of the vaccine was different from a "regulatory hold" required by health authorities.
It added that such pauses are normal in big trials, which can include tens of thousands of people.
J&J had kicked off its final 60,000-person trial just last month, the results of which were expected by the end of this year or early 2021.
Johnson & Johnson declined to elaborate on the participant's illness due to privacy concerns.
But the company says that some participants in studies get placebos, and it can be unclear whether a person suffering a serious illness in a clinical trial received a placebo or the treatment.