Johnson & Johnson has initiated a study pause of the COVID-19 vaccine trial over a patient exhibiting an ‘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 also says that adverse events even those that are serious are an expected part of any clinical study, especially large studies. The study aimed to test 60,000 participants across the US, Argentina, Brazil and several other countries.

The company also identified the difference between a “Study Pause” which is where the recruitment or dosing is paused by the study sponsor and is a standard component of a clinical trial protocol. A “regulatory hold” of a clinical trial is a requirement by a regulatory health authority such as the U.S. Food and Drug Administration.