Rapid at-home COVID-19 tests are fast, but the regulatory approval needed to get them in the hands of Americans is slow to come.
Why it matters: Rapid COVID-19 testing that can be done entirely at home could make a critical contribution to containment of the pandemic – and open a new frontier for more constant disease surveillance – but old assumptions about how to use diagnostics hold them back.
Driving the news: On Wednesday, the Biden government unveiled a $ 1.6 billion plan to accelerate COVID-19 testing in schools and other settings, strengthen test materials supply chains, and improve genetic sequencing surveillance.
- “We still don’t have enough tests, and we don’t have enough tests in all the places where it needs to be,” Carole Johnson, Biden’s test coordinator, told reporters.
In numbers: The number of COVID-19 tests conducted daily in the US is down about 30% from its peak a month ago.
- The US conducted a total of about 340 million tests – slightly more than one per person during the nearly a year-long pandemic.
Part of that dip is probably due to decreasing case numbers. But for proponents of rapid home tests, the drop also points to problems in the way we use tests – and the types of tests that are approved.
- COVID-19 tests have mostly been used to diagnose people who may be ill, and most of the approved tests use highly accurate but often labor-intensive PCR methods that require people to travel to clinics.
- The logistics and expense of manufacturing and running massive amounts of PCR tests make it difficult to constantly screen the population – which is exactly how cheaper, high-speed COVID-19 tests can be used at home.
Context: Pasadena, California-based Innova produces COVID-19 tests that cost less than $ 5 and work with the convenience of a home pregnancy test, yielding results in 15-30 minutes.
- For months, Innova has shipped millions of these tests to the UK, where they have been used as part of Prime Minister Boris Johnson’s “moonshot” mass testing program. Innova CEO Daniel Elliott says the company can currently make 15 million test kits per day, with plans to expand to 50 million per day by the summer.
- But Innova’s rapid test – which was first submitted to the FDA for approval in August – has not yet received emergency use clearance (EUA) needed for wide distribution, a status it shares with many other full-blown home rapid tests, such as one developed by Gauss and Cellex who use a smartphone to interpret results.
- “The FDA has been a bit of a challenge,” says Elliott. “We are used to looking at tests as if they should be almost laboratory quality, and there is simply not much experience with such a broad test that can be used for a variety of purposes.”
How it works: Rapid tests such as Innova’s search for a specific viral protein called an antigen.
- Antigen tests are less accurate than PCR. A study by Innova found that the test correctly identified 78.8% of the cases in a group of 198 samples compared to lab-based PCR results, a lower percentage that can result in more false positives and negatives.
- But advocates of rapid tests say the tests are especially good at identifying people who are in the contagious state of their disease.
- Which Combined with their superior ability to often test large numbers of people, they make them a “public health tool for suppressing outbreaks,” said Michael Mina, an epidemiologist at Harvard’s TH Chan School of Public Health.
What they say: “We consider home-use testing a top priority,” Jeffrey Shuren, a top FDA official who oversees testing, recently told The Hill. “And if they have their data and the data looks good, then we give permission.”
- The FDA recently awarded an EUA to a full home test produced by Ellume that reported very accurate results, although with a potential price of $ 30 or less, it would cost more to scale up.
The other side: Some experts – including from the UK, where quick tests are more common – are concerned that ordinary people would misinterpret the tests, further affect their accuracy, and that it would give them a false sense of security.
- But similar fears that arose when home pregnancy tests were first made available have never materialized, and proponents believe rapid screening could be used to “use this technology for other home tests in the future,” said Gauss CEO Siddarth Satish.
It comes down to: The U.S. health system was set up to provide the highest quality care – often at equally inflated prices – but COVID-19 testing is an area where fast and cheap can be the right approach in a real emergency.