So far, the FDA has granted emergency use authorizations to over 20 commercial COVID-19 diagnostic tests, panels and assays. The vast majority detect live infections by searching for specific nucleic acids—or the small pieces of RNA produced by the novel coronavirus—within swabs and respiratory samples.
A separate method, known as a serological test, would search for relevant antibodies in a person’s bloodstream, for evidence that the body produced an immune response to the disease.
This could be able to determine who has had and overcome an infection in the past—and could allow people to exit quarantine early, such as letting a nurse return to work at a hospital, for example.
Now, BD will begin offering a point-of-care antibody assay, which operates like a combination of a blood glucose test and a home pregnancy test. Using just a fingerstick of blood, the small test strip provides results within 15 minutes, showing multiple lines for a positive reading and a single line for negative.
Last month, the FDA said it wouldn’t authorize these types of tests the same way as molecular diagnostics. The agency described them as less complex, and said it would not object to their unreviewed use as long as they were clinically validated and not used as the sole method to diagnose an infection.
"Serology tests are important because they provide an additional piece of information to aid in characterizing possible prior exposure to SARS-CoV-2, especially since many infections are mild or asymptomatic in severity," said Dave Hickey, president of BD’s integrated diagnostic solutions division.
"Initial evidence suggests that nearly all patients infected with SARS-CoV-2 will have developed a detectable antibody response within days of symptom onset, at which time a negative serologic test, along with molecular diagnostics, could be helpful in ruling out COVID-19,” Hickey said. These antibodies are typically present in the middle to late stages of the infection.
Meanwhile, the FDA granted an Emergency Use Authorization April 2 to BD for its high-throughput RT-PCR molecular diagnostic, developed for its BD MAX platform in collaboration with BioGX.
The company's handheld serological test, developed by BioMedomics, was previously used by China’s Center for Disease Control. It requires no special equipment, and will be distributed by the medical supply company Henry Schein. BioMedomics has previously notified the FDA of its intention to market the test in the U.S. without seeking an official emergency authorization.
BD said it will make the test available this month and plans to supply more than 1 million tests in the future. BioMedomics described the test’s accuracy as having a sensitivity of 88.66%, and a specificity of 90.63%.
The FDA’s evolving policy on diagnostic tests in response to the crisis has tripped up other, smaller testing companies looking to combat the spreading coronavirus.
Earlier this week, a company called BodySphere published a since-retracted news release saying it had received an FDA emergency use authorization for its version of serological test. However, as the story spread, the agency confirmed to FierceMedTech that it had not granted any such antibody test a greenlight at that time.
The FDA granted its first official antibody test authorization April 1, to Cellex, for its IgG/IgM rapid, lateral flow immunoassay. It operates similar to BD's test, using a lined strip to test blood for antibodies.
According to a BodySphere spokesperson, the company was to act as the U.S. distributor for a test developed by Safecare Bio-Tech, a diagnostics firm based in Hangzhou, China. BodySphere’s CEO, Charlton Lui, later issued a clarification describing the announcement as a “misunderstanding,” and that the company would be able to sell the test kits while awaiting authorization under the FDA’s guidelines.
Previously, the agency clamped down on COVID-19 tests designed to be used at home, where a person would order a kit online, collect a sample themselves, and then mail the swab to a professional testing laboratory.
The FDA said the move was to protect against genuinely fake tests being shipped to U.S. consumers from overseas—however, the decision came as several telehealth companies were beginning to roll out kits, and after the agency loosened its oversight.
One home-testing company, Everlywell, said it believed they were following the FDA’s new emergency use regulations and was hours away from shipping 30,000 COVID-19 tests to consumers. Those tests were instead rerouted to hospitals and healthcare professionals, the company told FierceMedTech.
Meanwhile, the FDA reiterated its processes for granting emergency authorizations earlier this week, describing it as a relaxed standard based on less data compared to less-urgent public health situations. In many cases, the agency has given companies the green light in less than 24 hours after receiving their application.
In a statement, FDA Commissioner Stephen Hahn pushed back on critics of the agency’s process and claims that federal review has slowed the overall response to the spread of the virus.
“Every action the FDA has taken during this public health emergency to address the COVID-19 pandemic has balanced the urgent need to make diagnostic tests available with providing a level of oversight that ensures accurate tests are being deployed,” Hahn said.
“Our role is to determine if the tests developed by others provide accurate and reliable results, even when some would prefer that we let tests on the market without evidence that they work,” he added. “It’s critical that the tests used work. False results can also contribute to the spread of COVID-19.”
Editor's note: This story has been updated with BD's separate April 2 emergency test authorization.