Amid a nationwide run on at-home COVID tests and a shortage stemming from the tests' producers scaling back production a few months ago, CVS pharmacies are putting a limit on the number of test boxes customers can purchase at a time, online or in person.

The popular and previously widely available BinaxNOW tests by Abbott Laboratories are in short supply at many stores, prompting CVS to limit how many of the over-the-counter tests can be purchased at once. As Bloomberg reports, the company will limit customers to six boxes purchased online or four boxes when purchased in person — and the tests, which retail for about $24, come two per box.

The restart of in-person classes at schools around the country, coupled with the ongoing surge of Delta variant cases, has created a surge in demand for these rapid tests — though they remain less accurate than the molecular-based PCR tests that are done at most city-run testing sites.

CVS said in an email to customers that the per-customer limits on the tests would begin this week, "in order to serve our customers’ OTC testing needs, and due to high demand."

Abbott Laboratories may have made some business decisions in error this spring as demand for rapid tests plummeted in the U.S., following widespread vaccination efforts and a drop in COVID cases overall. That all changed this summer, and the New York Times reported that Abbott appeared to be caught by surprise — having already shut down one of two factories producing the at-home tests and allegedly ordering some supplies destroyed as well, before the surge in demand began. They also laid off 300 workers at their remaining production facility in Maine in July, only to have to scale back up very quickly — the company denies destroying any usable test components, and says because it retained much of its supplies, it was able to scale back up quickly.

"Just as we have done throughout the pandemic, Abbott is deploying our resources and expertise from all over the company to help quickly meet rising demand," Abbott said in a statement.

Another company producing slightly pricier at-home tests, Australia-based Ellume, also is trying to scale up, and Bloomberg reports it is trying to open a production facility in the U.S.

Ellume says its tests are in stock at CVS, Walmart, Target, and Everlywell.

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