Importance of Rapid Testing for COVID-19
Since the onset of the global coronavirus pandemic, efforts to stop the spread of the virus in the United States have focused on PCR tests for identifying positive cases. In light of ongoing supply-chain and processing problems with PCR tests, “rapid testing” has emerged as a necessary component of an effective containment strategy.
Rapid testing uses low-sensitivity tests to screen asymptomatic individuals for COVID-19. Common forms include anitgen-based tests and RT-LAMP, and the results are generally available within 15 minutes.
The U.S. Food and Drug Administration has issued an emergency use authorization for a low-cost rapid test, the SalivaDirect COVID-19 diagnostic test developed by the Yale School of Public Health.
Advantages of Rapid Testing
Rapid testing offers significant advantages over testing strategies that rely on PCR tests:
Cost – PCR tests generally range in cost from $50 to $150 per test. An antigen test costs between $1 and $5.
Time – People can administer their own antigen tests in their homes in the span of 15 minutes. PCR tests must be processed in laboratories, which often means waiting days – and sometimes weeks – to receive the results.
Scale – Millions of antigens tests can easily be manufactured and distributed.
Inexpensive, fast tests that can be produced on a major scale allow the level of frequent testing that is missing from current approaches to curbing the spread of COVID-19 in the U.S.
Need for Speed
Routine screening for COVID-19 does not require the diagnostic capabilities of PCR testing, which can detect remnants of coronavirus well after infected people are no longer contagious. That level of sensitivity is unnecessary when inexpensive rapid testing can detect when people are contagious and return results immediately. Low-sensitivity tests are still effective for identifying asymptomatic individuals when they are infectious.
Because PCR tests require days to learn the results, a regime of frequent rapid testing for asymptomatic individuals is more effective for driving down transmission of the coronavirus. People who receive a positive result from a rapid test can self-quarantine and confirm the result with a more sensitive PCR test.
Some rapid tests have been approved by the FDA. They require expensive and unscalable equipment. However, the FDA’s emergency use authorization of SalivaDirect could pave the way for the development of more lower-cost rapid tests such as could be used to control the virus.
Importantly, rapid testing programs could help facilitate reopening the U.S. economy and schools. Seven states – Louisiana, Maryland, Massachusetts, Michigan, North Carolina, Ohio and Virginia – are teaming with The Rockefeller Foundation in an interstate compact to purchase millions of antigen tests in an effort to expand the use rapid testing across the country.
What Can I Do to Help?
*Write to your Senator or Representative, asking them to fight for the immediate authorization and production of existing rapid tests, rather than requiring the strict clinical sensitivity of PCR. You can also send the letter by texting RAPID CONGRESS to 50409.
More Resources on Rapid Testing
- How to Beat COVID-19 with At-Home, Cheap, Frequent Testing – Explainer video from Harvard University epidemiologist Michael Mina on rapid testing
- Assessment of SARS-CoV-2 Screening Strategies to Permit the Safe Reopening of College Campuses in the United States
- Test sensitivity is secondary to frequency and turnaround time for COVID-19 surveillance