Updated at 5:38 p.m. ET
Two coronavirus studies have been put on pause by drugmakers as they investigate safety concerns.
The pauses are not uncommon or cause for undue concern, but they highlight how little is known about the combination of medications prescribed to President Trump following his COVID-19 diagnosis.
Johnson & Johnson paused all clinical trials of its experimental COVID-19 vaccine after a study participant became sick with an "unexplained illness."