Cheap, At-Home Coronavirus Tests Exist. Why Aren’t We Using Them?
Eight months into a global pandemic, we’ve learned a lot about the virus and how to respond, but a lot of questions remain unanswered. With schools and universities reopening and more employees going back into the office, effective testing for COVID-19 is more important than ever. In fact, we already have the technology for widespread, at-home testing. Why is it not more available?
First, we need to look at what’s gotten us to this point. We constantly require more testing, but a lack of effective technology severely limited availability in the early months of COVID-19. Combine that with a shortage of consumables like nasal swabs and chemical reagents and a limit in lab capacity, and we are looking at average test result times of two to three days at best, up to a week or more at worst. Most Americans have resigned themselves to accepting that this is the new normal, but we don’t have to settle for these numbers when alternative options exist. More on that in a minute.
The Food and Drug Administration (FDA) has granted emergency use authorizations (EUAs) for COVID-19 testing in three categories:
- Polymerase Chain Reaction (PCR) tests that look for viral RNA.
- Serum antibody tests that check your blood to determine if you were previously exposed to the virus and have since recovered. I took a test like this when I donated blood and found out that I have the COVID-19 antibodies.
- Antigen tests that detect viral proteins specific to the virus.
The FDA granted the first PCR EUA on Feb. 4 and the first serum test on April 1; however, they didn’t even release guidance on antigen testing until mid-May and waited until July 29 to release guidance for at-home antigen testing. Only two antigen tests have received EUAs by meeting the FDA’s strict 80 percent sensitivity rating, and both are subject to the same bottleneck of needing to be performed in a lab versus at home. The PCR-RNA tests are more sensitive in detecting trace amounts of the virus, but this can cause confusion as to what stage of the life cycle of the virus a patient is experiencing.
You may be asking, if these antigen tests have a lower sensitivity rating, why should we use them at all? Let’s use the example of an employee going to work. On Monday, he receives a negative test before work, spends the day at his desk, and contracts COVID-19 later that evening. On Tuesday or Wednesday, then, he would take more tests, realize he had the virus, and subsequently self-quarantine to prevent infecting others. The goal here is to provide enough tests that the employee could take one every day before work. When his viral antigen levels become high enough to make him infectious, the antigen test will be positive.
Contrast this with other forms of testing, in which the employee may never feel ill or display symptoms, so the likelihood of him going to get tested is very low. If he does go to a traditional facility to be tested once, he could still contract the virus later that week without ever knowing it. These infrequent tests make the chance of people unknowingly transmitting COVID-19 far more likely. Even if this employee never has the virus, waiting days to receive test results back from a lab may lead to him having to self-quarantine unnecessarily. The way we currently perform testing, millions of Americans can be asymptomatic carriers and never know.
Paper antigen strips should be the preferred method of COVID-19 testing. They’re cheap, accessible and, most importantly, fast. The technology works by testing for fragments of viral proteins in an individual’s nasal cavity or saliva, but can be administered in a non-laboratory setting (think a home, school, workplace) and display a positive or negative result within 10 to 15 minutes, much like a pregnancy test. This would enable us to identify who is infectious, as the antigen test is accurate when the viral load is high enough for a person to be contagious. The possibility of widespread rapid testing can bring our schools, workplaces and nation back up to speed without endangering millions of high-risk individuals.
This is not some pie-in-the-sky idea; these are real solutions that exist right now and should be a central part of our ongoing COVID-19 response. I sent a letter to FDA Commissioner Dr. Stephen Hahn urging him to revise guidance for non-laboratory rapid antigen tests, which would allow more paper antigen tests to receive EUAs. In the interest of public health, time is of the essence and revised guidance would jumpstart production and enable Congress to take funding action to get these tests into people’s homes for daily use.
America has shown incredible resilience in the face of COVID-19. Many of you have stayed home to care for children and limit contact with friends and many of you have continued going to work to care for the sick and keep our food supply chain up and running. In just a few months, we went from knowing next to nothing about the virus to performing more than 70 million tests in the U.S. Yet we are far from finished, and if we want to move the country into the next phase of recovery, we require creative solutions. The evidence is clear: antigen testing works, and therefore must be part of this solution.