Three boxes of a take-home rapid antigen COVID test sit on table in Ellsworth on Wednesday, Sept. 8, 2021. Credit: Bill Trotter / BDN

WASHINGTON — President Joe Biden is betting on millions more rapid, at-home tests to help curb the latest deadly wave of the COVID-19 pandemic.

Surging infections are overloading hospitals and threatening to shutter some classrooms. However, the tests are quickly disappearing from pharmacy shelves in many parts of the U.S., and manufacturers say it will take them weeks to ramp up production. Production was decreased after demand for the tests plummeted in early summer.

The large commercial labs that process most tests performed at hospitals and testing sites report plenty of capacity. LabCorp, one of the biggest laboratory chains, said last week it was delivering results for 150,000 tests daily, with the ability to double that number.

Rapid tests can be done anywhere and have a 20-minute turnaround time, but most school testing programs still rely on tests processed in labs, which return results in a day or two.

The Department of Health and Human Services announced a $2 billion plan to purchase rapid tests. For now, retail chains like CVS and Walgreens have placed limits on how many at-home tests customers can buy.

Abbott Laboratories, the country’s largest rapid test maker, says it is currently producing “tens of millions” of its BinaxNOW tests per month and working to increase capacity in the coming weeks.