In the early stages of the COVID-19 pandemic, the U.S. Food & Drug Administration authorized SARS-CoV-2 tests for diagnostic purposes only. On March 16, the FDA issued a new supplemental template to streamline authorization for test developers seeking Emergency Use Authorization (EUA) of certain tests for screening and serial testing1. The agency also released a fact sheet outlining helpful considerations to assist groups in determining which test to use for prospective screening programs.
Some groups are already finding value in alternative uses of SARS-CoV-2 diagnostic tests. The question then becomes — if employed as a screening tool, could rapid antigen testing provide a long-term solution in the fight against COVID-19?
Polymerase chain reaction (PCR) testing has traditionally been — and remains — the gold standard for SARS-CoV-2, identifying active infection by detecting viral genetic material to confirm diagnosis. Typically conducted at a hospital or reference lab, PCR testing offers the advantage of high throughput and accuracy. However, results can take a minimum of 4 to 6 hours to receive and the tests can be more expensive to employ than their antigen counterparts.
By detecting viral proteins, rapid antigen tests offer much faster results, usually within 15 to 30 minutes. In addition, because they don’t require instrumentation or lab processing, they’re easy and convenient to use in doctors’ offices, at point-of-care outlets and in other settings. However, rapid antigen’s sensitivity isn’t as high as with PCR testing.
Screening already plays a critical role in the early detection of many diseases and illnesses, including a range of cancers, heart issues, and blood and urine disorders. In the case of COVID-19, using rapid antigen tests in a screening capacity among groups of people may afford the ability to more readily detect the presence of the virus, allowing for the opportunity to quickly triage both symptomatic and asymptomatic patients and reduce the overall spread of infection.
Rapid antigen testing is already being put to use in some non-traditional settings; for example, in sports team “bubbles,” at colleges and universities, and at airports to monitor passengers traveling internationally.
Therefore, it stands to reason that rapid antigen screening could become key to isolating positive COVID-19 cases, ultimately slowing the spread of the virus in populated locations such as schools, churches and places of worship, office buildings, and at community events. Rapid antigen testing may also prove to be beneficial for screening in hard-to-reach rural areas and in underserved neighborhoods with low access to health care.
There’s still a great deal we don't know about COVID-19, but as technology and innovation strive to keep pace with the evolution of the virus, it behooves us to consider new approaches to diagnosis, screening and treatment.
With further research, along with CDC and FDA guidance, putting rapid antigen tests to use as a screening tool might just contribute to a faster reduction in COVID-19 restrictions, and a welcome return to life as we knew it pre-pandemic.