The federal government late last week released an updated blueprint for distributing the second wave of nearly 12,000 point-of-care COVID-19 testing units destined for nursing homes, with a significantly wider definition of hotspots than the initial round.

The Centers for Medicare & Medicaid Services (CMS) has designated about 11,800 facilities as targets for the second wave of antigen testing devices, according to the most recent database update, with nursing homes in “hot spots” again assigned first priority.

But unlike the first wave, which saw about 2,400 facilities receive the machines, those “hot spots” won’t be confined to individual counties — instead, the entire states of South Carolina, Alabama, Arizona, Florida, Louisiana, Idaho, Georgia, Mississippi, California, Texas, and North Carolina are at the top of the list.

CMS will then rank facilities in each state by the total prevalence of COVID-19 within each county; following that, priority will be given to nursing homes that have self-reported an inability to secure adequate access to testing, then to facilities with the highest numbers of cases and deaths.

“We anticipate that all facilities listed in this document will receive a POC testing device before the end of September 2020,” CMS indicated in the new priority list.

The news comes after the Department of Health and Human Services (HHS) last week invoked the Defense Production Act to significantly ramp up purchases of the antigen testing units from Becton Dickinson (BD), which along with manufacturer Quidel Corporation will supply the approximately 14,000 machines included in the initiative.

BD will shoulder most of the load, with 9,000 units on order from HHS, a spokesperson confirmed to SNN last week.

But the second wave of devices has also been met with scrutiny from providers and health experts, who questioned the accuracy and efficacy of the antigen units in a story published by Kaiser Health News.

The federal government has been upfront about the fact that the antigen method is not as reliable as the “gold standard” polymerase chain reaction (PCR) tests; in fact, operators are still told to confirm all negative antigen tests with a follow-up PCR check, and in the meantime treat such residents as presumptively positive until the PCR results come back.

The Kaiser report put the false negative rate — that is, the chance of a person with COVID-19 erroneously appearing to be clear — sits at 15% for the BD devices and 3% for Quidel.

Adm. Brett Giroir, the top HHS official in charge of the testing plan, in July emphasized that a positive antigen result is largely reliable.

“If you get a positive, these are essentially 100% specific. If you have a positive it is positive: You can bet the farm on it. Never 100%, but literally they are operating at about 99-plus percent specificity. If you get a positive, it’s real,” Giroir said.

There’s also the question of how reliable the tests are for screening asymptomatic staff and residents, a primary driver of infections and outbreaks in nursing facilities.

Both companies have indicated that the devices should be used to test patients within five days of displaying symptoms, Kaiser reported, with a BD spokesperson indicating that the company’s units “should not be used on asymptomatic individuals”; Quidel deferred to Food and Drug Administration (FDA) guidelines that endorse the use of asymptomatic tests in some situations, according to the outlet.

The Centers for Disease Control & Prevention (CDC) in its own guidance noted that the science of antigen tests for asymptomatic patients remains light.

“There are limited data to guide the use of rapid antigen tests as screening tests on asymptomatic persons to detect or exclude COVID-19, or to determine whether a previously confirmed case is still infectious,” the CDC wrote in guidance released earlier this month. “Clinicians should understand antigen test performance characteristics in order to recognize potentially false negative or false positive results and to guide patient management.”

The ongoing costs of the program also remain a concern for operators: After the initial distribution of testing supplies, facilities will be on their own to buy replenishment orders through a special “concierge” portal that BD and Quidel are required to establish, according to Giroir.

Supplies of the required assays are expected to remain “tight” through the end of September as the manufacturers ramp up production, but Giroir last week assured operators that a sufficient supply will eventually be made available.

That said, not only are facilities on the hook for the cost of the assay refills, but each negative may necessitate a second PCR test — the cost of which nursing home operators generally must cover.*

“I just have a lot of skepticism,” Brendan Williams, president of the New Hampshire Health Care Association, told Kaiser. “Basically you’re giving some lousy tests for nursing homes and you’re making them pay for them. I don’t see that as a win; I see that as a risk.”

*Update, August 26, 2020: Updated federal guidelines now indicate that follow-up PCR tests are not required or even recommended in all situations when antigen tests return a negative result. In short, the decision to double-check depends on context, with a second test recommended in the case of outbreaks but not necessary for routine surveillance testing programs.