Missouri's health director has resigned.

Republican Gov. Mike Parson on Tuesday announced the departure of Department of Health and Senior Services Director Dr. Randall Williams.

Williams was appointed to the job in 2017 by Parson's predecessor, former GOP Gov. Eric Greitens. Williams helped lead the state's response to the coronavirus pandemic and is leaving amid the vaccine rollout.

Parson says he's naming his deputy chief of staff, Robert Knodell, to be the state's acting health director.

Parson says Knodell has also been leading the state's COVID-19 response. But Knodell doesn't have a medical background as Williams does.