Manufacturer of the most accurate Home COVID-19 Tests on the market say they have been left out of the Biden administration again last round of free orders via COVIDTests.gov, which for the seventh time are limited to less sensitive “Antigen” testswhich are usually the cheaper option in drugstores.

Federal health officials justified the Millions they spent on equipment manufacturers for the latest waves as crucial to subsidizing U.S. factories capable of producing tests ahead of another potential pandemic, at a time when demand has evaporated.

Most of the taxpayer money went to makers of low-cost rapid antigen tests such as Access Bio in New Jersey and iHealth in California, rather than to more accurate “molecular” alternatives that the Food and Drug Administration had also greenlighted.

A spokesman for the Strategic Preparedness and Response Agency, which awarded the contracts, did not immediately respond to a request for comment.

What are the most accurate home tests for COVID-19?

The FDA has currently approved only four brands of over-the-counter molecular tests for COVID-19. These are the most accurate but also the most expensive options:

• Pfizer’s Lucira sells a one-time test with the lowest purchase cost, starting at $39.99, that detects both COVID-19 and flu. The FDA says results take about 30 minutes to come back, and each test has an 18-month shelf life.
• Aptitude Medical Systems sells a “starter pack” that includes a reusable reader and two test kits for $99.97. The FDA says results take about 30 minutes to come back and the tests have a shelf life of about 18 months. Additional test kits cost $24.99.
• 3EO Health sells a “starter kit” that includes a reusable testing device and two swabs for $195. According to the FDA, results take about 30 minutes and the tests have a four-month shelf life. Additional swabs and “test keys” cost $39.90 for a pack of two.
• Cue Health sells a reusable “reader” that costs $199. Test kits are currently out of stock on the company’s website. According to the FDA, results take about 20 minutes to come back and the tests have a shelf life of about four months.

These prices are several times higher than antigen testing options, although device manufacturers say COVID-19 tests are generally available for Flexible spending account or health savings accounts and may be reimbursable under some health insurance plans.

A molecular test takes longer to produce results because the devices must create chemical reactions to amplify any traces of the virus that less accurate tests might otherwise miss.

This corresponds to a stated sensitivity – the accuracy in correctly detecting infections – of over 90%, even when people do not show symptoms of the virus.

In contrast, the FDA warns that Americans who rely on antigen tests should be prepared to use multiple kits if they fear they may be infected.

Because the risk of a false negative result is higher with antigen options, especially in the early stages of infection, people should repeat their tests several days after the first negative test, the agency recommends.

This difference is important early in a COVID-19 infection because people are most contagious, according to the CDC, with the highest amount of infectious virus detected in patients “within a few days before and after” the onset of symptoms.

The CDC says in its latest guidelines that a negative result on antigen tests can still be a useful “option” for assessing when it is safer to end isolation at the end of an infection and provides a “rough approximation of whether a person is still infectious to others”.

What brands of antigen tests are shipped by COVIDTests.gov?

Manufacturers of COVID-19 antigen tests told CBS News they are continuing to supply kits through COVIDTests.gov under contracts awarded to a dozen manufacturers last year.

A few test brands have been able to obtain “traditional marketing authorization” from the FDA to continue selling their tests after the pandemic and during the emergency shutdown. These include:

• CorDx sells two-packs for $14.99 that deliver results in 10 minutes
• iHealth Labs sells two-packs for $17.98 that deliver results in 15 minutes
• InBios International sells packs of two for $8.50 that provide results in 20 minutes
• Quidel Corporation sells two-packs for $16.99 that deliver results in 10 minutes

Other tests remain under emergency use authorization, including OraSure’s InteliSwab kit. This “more accessible” test will again be sent free of charge to blind or visually impaired Americans this year through the Administration for Community Living.

Although less accurate than molecular tests, ASPR says its antigen tests will still be able to “detect the COVID-19 variants currently circulating” this year.