ATLANTA (AP) — Georgia’s largest school district has joined the growing ranks of those that will require students and employees to wear masks.

Gwinnett County is the latest to reverse a mask-optional policy. The district cites new guidance from the U.S. Centers for Disease Control and Prevention.

The move comes as new COVID-19 infections are spiking in Georgia. Officials reported more than 3,700 positive COVID-19 tests on Tuesday. That’s more than double the day before and the highest number since late February.

The Savannah-Chatham and Clarke County school systems also said everyone must wear a mask. Emory University said all employees must get vaccinated.