US drugmaker Johnson & Johnson said on Monday it temporarily halted clinical testing of its COVID-19 vaccine because one of its participants became ill.
“We have temporarily halted the administration of new doses in all of our clinical trials of the covid-19 vaccine, including the phase 3 ENSEMBLE trial, due to unexplained illness in a study participant,” the company said in a statement.
The hiatus means that the online enrollment system has been closed for the 60,000-patient clinical trial, while the independent committee on patient safety is convened.
J&J said that serious adverse effects were “an expected part of any clinical trial, especially a large one.” Based on company guidelines, they can stop a study to determine if the adverse effect was due to the drug in question and if the study can be resumed.
Phase 3 of the Johnson & Johnson study began recruiting volunteers in late September, with a goal of enrolling up to 60,000 participants at more than 200 locations in the United States and around the world.
The other countries where the tests were conducted are Argentina, Brazil, Chile, Colombia, Mexico, Peru and South Africa.