US drug maker Johnson & Johnson on Monday announced that it has paused the advance clinical trial, ENSEMBLE, of one of its vaccines after one of its participants had become sick. The company is conducting Phase III trials of its coronavirus vaccine candidate.
In a statement, Johnson & Johnson has said, "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 has further said, “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.”
Johnson & Johnson has not yet revealed details about the unexplained illness but has stopped trials while doctors find out if the illness was caused due to the vaccine or was a coincidence. "Adverse events -- illnesses, accidents, etc. -- even those that are serious, are an expected part of any clinical study, especially large studies," the company added.
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. Two weeks ago, the company kicked off a final 60,000-person trial of a single-shot Covid-19 vaccine that potentially would simplify distribution of millions of doses compared with leading rivals using two doses.
Rival vaccines from Moderna Inc, Pfizer Inc and AstraZeneca all require two shots, which make them much more difficult to administer.