By CBS3 Staff

PHILADELPHIA (CBS) — Johnson & Johnson has paused its trial of a COVID-19 vaccine after one of its volunteers experienced an unexplained illness. The New Jersey-based drugmaker has not said what the illness is.

Researchers will now check to see if the participant’s symptoms can be linked to the vaccine or if it’s a coincidence.

This is the second Phase 3 coronavirus vaccine trial to be paused.

Just last month, AstraZeneca paused its trial because of a neurological complication in a volunteer in Britain.