New program seeks to combine COVID-19 antigen and molecular tests that can both be performed at the point of care and provide rapid results
The US Department of Health and Human Services (HHS) announced the launch of a pilot program in five states, intended to better integrate point-of-care (POC) COVID-19 testing into current coronavirus testing strategies.
Accessible testing that provides reliable and rapid results has been a goal since the beginning of the pandemic. Initial PCR tests were quite reliable with most having excellent sensitivities and specificities. However, PCR tests fail to provide test results that can be obtained quickly or at the point of care.
Antigen testing became the next step toward implementing a national COVID-19 testing strategy, emerging as a widely available testing methodology in late June 2020. Antigen testing allows for POC testing and provides results in minutes, not days.
With rapid turnaround time and increased accessibility, COVID-19 antigen tests quickly became a popular option, particularly for political leaders. By mid-July, HHS had ordered antigen tests for 2,000 nursing homes and would soon follow up with antigen tests for over 14,000 nursing homes across the country. (See First Wave of Testing Begins as HHS’ Large Scale Distribution of SARS-CoV-2 POC Antigen Tests Takes Shape in Hot Spots.)
However, greater use of COVID-19 antigen tests revealed a downside: That is a higher rate of false positives than would be experienced with PCR testing. For some, this is an acceptable tradeoff, even though false positive results can cause workflow disruptions, quarantines, and closures that are often unnecessary, especially in low-prevalence areas. And, to add PCR confirmation testing as a follow-up to positive antigen testing revives the problem of longer turnaround time.
HHS Cue Pilot Program Creates Hybrid Testing Strategy
The new HHS pilot program announced Nov. 19, 2020, seeks to resolve ongoing turnaround time and accuracy issues by using a new POC COVID-19 testing strategy that involves a hybridization of antigen testing and rapid POC molecular testing. HHS specified integrating Cue Health’s COVID-19 diagnostic test into existing testing strategies.
Cue Health’s molecular COVID-19 test does not rely on PCR testing, and, instead, uses isothermal nucleic acid amplification technology. This technology allows for the identification of SARS-CoV-2 specific genetic material in 20 minutes at the point of care. This molecular test has a sensitivity of 98.7% and a specificity of 97.6%, making it much less likely to provide a false positive than antigen testing.
Officials are examining multiple potential uses for the Cue COVID-19 Test in POC testing. They include repeat testing on positive antigen tests and testing negative antigen tests where COVID-19 is suspected. This pilot program begins with Florida, Louisiana, New Jersey, Texas, and Alaska and is anticipated to include 100,000 tests per day by spring 2021.
“The Cue Health testing system will undoubtedly be a valuable addition to our testing ecosystem,” said Adm. Brett Giroir, MD, HHS Assistant Secretary for Health. “Having a highly specific and sensitive POC molecular test could dramatically improve infection control at nursing homes and other institutional settings especially.”
Potentially Fast Tracks Cue Test into Institutions and Other Communities
Continued Giroir, “Our strategy continues to be to get the right test to the right person at the right time. We recommend that nursing homes and other institutions follow a layered approach to testing—using rapid, inexpensive, and frequent point-of-care tests for screening staff and verifying the results with more sophisticated molecular tests when the situation warrants. With Cue’s COVID-19 Test, verifying the antigen test results can be done on the spot in many cases. The pilot program will help us determine how well the Cue test will be adapted in institutions and communities.”
Clinical laboratory leaders should be aware of the continued emphasis on POC testing and rapid test results. While antigen-based testing has suffered some setbacks and a decrease in its previously high perception by the public (See Clinical Laboratories May Benefit as Some Nursing Homes Hesitate to Implement Point of Care COVID-19 Antigen Testing), rapid, POC testing for COVID-19 continues to accelerate into wider practice.
Clinical laboratories in states where the HHS pilot program is not being implemented may want to consider POC testing using the Cue Health COVID-19 test as a verification test for antigen testing. While the results of the HHS Cue pilot program are unknown, the overall conceptual basis is sound, and clinical laboratories that implement this strategy now in supporting POC testing may be better positioned to benefit.
—By Caleb Williams, Editor, COVID-19 STAT
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