Johnson & Johnson pauses Covid vaccine trial as participant becomes ill

Johnson & Johnson has temporarily halted its Covid-19 vaccine trial because one of its participants became sick.

"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.

The pause means the online enrollment system has been closed for the 60,000-patient clinical trial while the independent patient safety committee is convened.

The participant's illness is being reviewed and evaluated by an independent data and safety monitoring board as well as the company's clinical and safety physicians, the company added.

J&J, which reports quarterly financial results on Tuesday morning, said that such pauses are normal in big trials, which can include tens of thousands of people.

However, J&J's move follows a similar one by AstraZeneca Plc. In September, AstraZeneca paused late-stage trials of its experimental coronavirus vaccine, developed with the University of Oxford, due to an unexplained illness in a UK study participant.

While trials in the UK, Brazil, South Africa and India have resumed, the US trial is still on hold pending a regulatory review.

Last month, J&J said its experimental COVID-19 vaccine produced a strong immune response against the novel coronavirus in an early-to-mid stage clinical trial, following which the company kicked off a final 60,000-person trial, whose results had been expected by the end of this year or early 2021.

Johnson & Johnson declined to elaborate about the illness due to privacy concerns. It did say that some participants in studies get placebos, and it was not always clear whether a person suffering a serious adverse event in a clinical trial received a placebo or the treatment.

(with inputs)