After scaling back coronavirus testing last month, Indiana is ramping back up.

Indiana is redeploying National Guard troops who helped nursing homes at the height of the pandemic last winter. Troops will assist local health departments with testing. State health commissioner Kris Box says the state department is returning staffers to testing duty, and says she expects to announce a deal next month with an outside group to expand testing further in October.

The number of tests has doubled in three weeks as the Delta variant gains momentum. Nearly 46,000 tests were reported on Tuesday, the biggest one-day total in four months. That’s led to long and frustrating wait times.

Box says one factor in the increased demand is the start of the school year. The Delta variant has hit kids harder than previous strains of the virus, with twice as many cases last week among kids than there were just two weeks earlier. Box says that’s created a need for more tests, with parents concerned because their kids have symptoms, and with kids who had close contact with an infected classmate and can’t return to school without a negative test.

People 12 and up are eligible for the vaccine, but vaccinations among teenagers remain far below adult rates. Box and Governor Holcomb are reemphasizing the vaccine is the most important weapon to stop the virus’s spread and to prevent serious illnesses.

Indiana still has more than 600 testing sites, with at least one in all but four counties. But Box says many testing sites have reduced capacity and hours. And she predicts demand will continue to rise even if the Delta outbreak slackens, as cold and flu season begins and people get tested to find out if their symptoms are from COVID-19 or something less serious.