The FDA has authorized a Quest Diagnostics (NYSE:DGX) test for COVID-19 to be used with pooled samples — the first such authorization by the agency since Dr. Anthony Fauci, the nation’s leading infectious disease specialist, started publicly discussing pooled-sample testing about three weeks ago.
The authorization, announced Saturday, permits the pooled testing of up to four individual swab specimens. If the pooled sample tests positive, each patient’s sample will be tested individually. The FDA is touting pooled-sample testing as more efficient than individual tests, meaning fewer testing supplies are used and more tests can be run at the same time, allowing patients to receive their results more quickly in most cases. Pooled testing is most efficient in areas with low prevalence, meaning most results are expected to be negative, according to the agency.
Quest’s SARS-CoV-2 rRT-PCR landed the first EUA for pooled testing as part of a reissued EUA.
The FDA acknowledged concerns that combining samples may make it more difficult to detect positives, because pooling in the laboratory dilutes any viral material present in the samples. But the agency said Quest’s validation data demonstrates that its test correctly identified all of the pooled samples that contained a positive sample. None of 3,091 total specimens from a population with a prevalence rate of 1% to 10% percent, if pooled, would have been incorrectly determined to be negative (95%CI 0.0-0.1%), according to a statement by Secaucus N.J.-based Quest.
“This EUA for sample pooling is an important step forward in getting more COVID-19 tests to more Americans more quickly while preserving testing supplies,” said FDA commissioner Stephen Hahn. “Sample pooling becomes especially important as infection rates decline and we begin testing larger portions of the population.”
Infection rates have been soaring in certain states, including Texas, Georgia, Florida and Arizona.
Pooling is used routinely in blood banking to screen donated blood for a variety of viruses, among other applications, according to Quest. The company expects to deploy the technique at its laboratories in Chantilly, Va., and Marlborough, Mass., by the end of this week with additional laboratories to follow.
“As COVID-19 continues to spread around the country, access to timely, quality laboratory testing is critical to patients and an effective public health response,” said Quest president & CEO Steve Rusckowski in the statement. “Pooled specimen testing is a proven technique that will help us to optimize testing capacity at this critical time for our country.”
It is not a panacea, added Dr. Jay Wohlgemuth, the company’s chief medical officer. “Pooling will help expand testing capacity but it is not a magic bullet, and testing times will continue to be strained as long as soaring COVID-19 test demand outpaces capacity,” Wohlgemuth said. “Each of us can practice behaviors that will reduce COVID-19 infections in our communities, so our national healthcare system can better respond to this crisis.”
The Quest test, initially authorized on March 17, 2020, remains authorized to test individual samples collected by a healthcare provider. It is also still authorized for use with individual nasal swab specimens that are self-collected at home or in a healthcare setting using an authorized home-collection kit when determined to be appropriate by a healthcare provider, according to the FDA.