Those with fevers and runny noses have agonized over this dilemma for three pandemic years: "Is this COVID, which has killed over a million Americans, or is it a more familiar flu?" The symptoms frequently overlap. But, the US Food and Drug Administration has now approved the first at-home test that can discriminate between COVID and the flu. The test can distinguish between three respiratory viruses—the germ that causes COVID, SARS-CoV-2, and influenza A and B—with excellent accuracy from one swab in just 30 minutes.
Regrettably, the product's future is still up in the air. Late in February, just two days after Lucira Health, the test's maker, disclosed that it had applied for Chapter 11 bankruptcy protection, the FDA granted the test emergency use authorisation.
Prior to the FDA's emergency use authorization, the flu-and-COVID test was previously approved for use in hospitals and doctor's offices as well as at home in Canada, Europe, and the United States. In the United States, it is now legal to sell it straight to customers without a prescription. Its technology is more similar to complex polymerase chain reaction (PCR) testing conducted in laboratories than it is to the widely used home antigen tests. Similar to PCR, Lucira's product amplifies viral genetic material to a readily recognizable level by replicating it using enzymes. Compared to antigen testing, it is more sensitive.
The product is the first flu and COVID home test combination that has been approved for use in the United States. In the past, attempts have been made to create antigen tests for the flu, but Susan Butler-Wu, a clinical microbiologist at the Keck School of Medicine of the University of Southern California, says the assays couldn't achieve a high enough degree of accuracy. The antigen performance for the flu is "actually fairly terrible," she says, adding that this has long been recognized.
The item is the first flu and COVID at-home test combination that has received US approval. Antigen tests for the flu have already been developed, but Susan Butler-Wu, a clinical microbiologist at the Keck School of Medicine of the University of Southern California, claims the assays couldn't achieve a high enough level of accuracy. According to her, the antigen performance for the flu is "really very awful," and this has long been known.
The test also revealed 99.9% of samples to be free of influenza B, but this information isn't complete because there aren't enough cases of influenza B circulating for researchers to undertake a clinical investigation. The FDA has mandated that Lucira continue gathering information on influenza B.
In contrast to PCR, Lucira's test makes use of a procedure known as loop-mediated isothermal amplification (LAMP). According to Butler-Wu, it is "sort of like [PCR's] cousin." In order to amplify genetic material, PCR runs a sample through numerous distinct temperature cycles. LAMP, on the other hand, can operate at a single temperature, making the processing apparatus straightforward enough to be utilized at home. The single-use plastic device is powered by two AA batteries because Lucira's test does require electricity.
Since 2020, the FDA's emergency authorizations have permitted COVID vaccines, medications, and tests to hit the market. Lucira's test won't be deauthorized at that time since these authorizations are different from the public health emergency that the Biden administration intends to stop in May.
How Lucira's bankruptcy will impact the product's accessibility is still unknown. A company representative told Scientific American that the company has created several test kits in anticipation of approval, which it can now sell. In order to resume producing its goods, which also include COVID-only, LAMP-based home exams, Lucira is attempting to sell its company under Chapter 11. While the company's at-home COVID-only tests are offered on Amazon and through its website, it has not yet said when the new combination test will be released or where it will be marketed.
The cost of the at-home solution has not yet been disclosed by Lucira, although healthcare providers can purchase it for $99 at this time. According to Lucira's web site, Canadian customers have been able to purchase it for 98 Canadian dollars, or around $72. Contrarily, the well-liked COVID antigen test, BinaxNOW, from Abbott Laboratories costs roughly $12 each test. However, the FDA advises utilizing repeated assessments at two-day intervals for antigen tests, depending on a person's symptoms and viral exposure, which raises the overall cost.
One benefit of a test that can distinguish between COVID and the flu is that it will be simpler for medical professionals to swiftly determine the best course of action. Butler-Wu states, "For the flu, I might receive Tamiflu, and then for [COVID], I might get Paxlovid." So, having that knowledge might be quite beneficial in that situation.
According to David Peaper, a medical microbiologist at the Yale School of Medicine, receiving the results of a test results at home can expedite an often lengthy diagnosis and treatment process. Several of these treatments must be started within a particular number of days of the commencement of the sickness since they are highly time-sensitive, he adds. However, the combo test might be less useful outside of flu season. While the virus is not active, Peaper advises against testing for the flu since doing so runs the danger of producing false-positive findings that could mislead both patients and medical professionals over the appropriate course of treatment.
According to Peaper, the rise in home testing during the pandemic has altered how patients and physicians approach the diagnosis and treatment of infectious diseases. The only comparable FDA-approved home tests prior to the emergence of COVID were for HIV. Now, strep throat and respiratory syncytial virus assays are being developed (RSV). According to Peaper, "I think it's definitely changed expectations." The fact that patients can perform these tasks at home is clearly demonstrated.