NEW YORK – With backing from the US Centers for Disease Control and Prevention (CDC), several large national laboratories have launched molecular tests for detecting avian influenza A virus, H5N1.
Demand for testing remains low, but one lab firm suggested a recent health advisory from the CDC recommending more rapid subtyping of influenza A-positive specimens to test for avian flu could drive volumes.
Several lab stakeholders said the industry is significantly better prepared to meet a spike in H5N1 test demand than it was to handle SARS-CoV-2 testing needs at the beginning of the COVID-19 pandemic.
In September, the CDC awarded $41,444.07 to ARUP Laboratories, $75,750.00 to Laboratory Corporation of America, and $325,072.00 to Quest Diagnostics to support development and validation of tests for H5N1.
The awards were part of a larger funding package from the CDC that the agency said were intended to "strengthen our national laboratory system to support readiness and response activities at all levels of public health and across multiple pathogen and condition types." In addition to the funds for H5N1 test development, the package included contracts worth up to $118 million to Labcorp, Quest, ARUP, Ginkgo Bioworks, and Aegis Sciences "to improve the efficiency and accuracy of laboratory testing and the situational awareness provided by use of laboratory data during and outside of public health emergencies" including "by improving specific laboratory processes and data sharing."
Quest launched its H5N1 test at the end of October, Labcorp launched its test in December, and ARUP launched its test at the beginning of January. Sonic Healthcare's American Esoteric Laboratories also offers H5N1 testing.
Speaking to 360Dx shortly after Quest launched its H5N1 test, Elizabeth Marlowe, executive scientific director at the company, said the CDC funding had been an important driver of its H5N1 test development work given the uncertain market for the assay.
"It's a really hard business sell," she said. "Use your resources. Use your money. And you may never sell a test. [The CDC award] certainly helped a lot."
Marcia Eisenberg, senior VP and CSO at Labcorp, said the firm's decision to develop and launch an H5N1 test had been made largely independent of the CDC funding.
"We develop somewhere between 50 and 125 tests per year," she said. "Our goal and role is to keep our test menu moving forward, looking at scientific information. So this is something that we would do routinely, but in conversation with the CDC."
During a December press event hosted by the College of American Pathologists (CAP), Ben Bradley, medical director of virology at ARUP, suggested that the lab industry is much better prepared for H5N1 than it had been for COVID-19 and highlighted the CDC awards as well as the fact that labs have been able to leverage their existing flu testing businesses to prepare for H5N1 testing.
In an email to 360Dx, Bradley also cited as helpful the US Food and Drug Administration's decision in July to provide enforcement discretion for H5N1 tests under its current rules on laboratory-developed tests, meaning that clinical labs certified for high-complexity testing under CLIA are not required to obtain premarket approval from the FDA before offering H5N1 tests.
"Initially, there was some concern that because of the final rule, any LDT for H5 would require FDA approval in the absence of a declared [public health emergency] and issuance of an [Emergency Use Authorization] for H5 testing," Bradley said. "That could have led to test access delays."
CAP President Donald Karcher, likewise, said that to his eyes, the FDA and CDC "are very much ahead of the curve on H5N1."
"We've been pretty impressed with them," he said, noting that "testing is being developed such that if suddenly this becomes a pandemic, testing could be made broadly available pretty quickly. We're in a much better place right now than we were at an equivalent time with COVID."
Karcher said that CAP is also working to help hospital labs prepare to launch H5N1 testing in the event that it is broadly needed. He said that in the case of COVID-19, large national labs initially struggled with turnaround time, undermining the usefulness of testing.
"We cannot have that happen again, so we are all very focused on making sure widespread testing can be available very quickly with short turnaround time," he said.
To that end, CAP is preparing to develop H5N1 proficiency testing materials if needed, Karcher said.
Labcorp's Eisenberg said the company had seen little demand for the test thus far, noting that the development effort was "really preparatory, in case there is a need."
Quest did not provide specifics on H5N1 test volumes, but company spokesperson Jennifer Petrella said the company continues to receive orders for the test and is accepting both respiratory and conjunctiva specimens. She also noted a recent CDC health advisory recommending that hospital patients positive for flu A receive subtyping within 24 hours to determine if the virus falls into one of the common seasonal flu A subtypes, H1 or H3. If it does not, the agency recommends the sample be tested for the H5, avian flu, subtype.
Petrella said Quest is working to make sure hospitals are aware of its H5N1 test offering and noted that the company provides testing to around half of US hospitals each year.
Bradley noted that despite the progress made, challenges around H5N1 testing remain. In particular, he said, many individuals at the highest risk for infection, such as dairy workers, have less contact with the healthcare system and may be reluctant to undergo testing as a positive result could lead to missed days of work. The CDC has confirmed 67 human H5N1 cases in the US, but Bradley said serology studies suggest that this is likely an undercount of the true case number.
On Jan. 3, the US Department of Health and Human Services announced $306 million in funding for avian flu monitoring and preparedness, including $103 million from the CDC for increased monitoring of exposed individuals and for outreach to high-risk populations. The funding also included $8 million from the CDC to manufacture, store, and distribute avian flu diagnostics.
Since the Trump administration took over, the notice of the award has since disappeared from the HHS website. The agency did not respond to questions as to whether the funds were still being dispersed as planned or if they had been frozen or canceled.