Healthcare organizations in the SeroNet Capacity Building Centers network, managed by the Frederick National Laboratory for Cancer Research, are gathering data on SARS-CoV-2 antibody test results and working to determine their clinical significance.
The project is a component of the Serological Sciences Network, or SeroNet, a network of biomedical research institutions formed for coordinated study of the immune response to COVID-19 and led by the National Cancer Institute.
On any given day, physicians across the U.S. will order a SARS-CoV-2 antibody test for tens of thousands of patients.
Northwell Health, New York state’s largest health care provider and one of the four SeroNet Capacity Building Centers, has performed 1.2 million antibody tests, nearly 2,000 samples daily. Many were ordered by physicians within its network. Labcorp, one of the nation’s largest clinical laboratory networks, has performed more than 7 million antibody tests since the pandemic began, a sum equating to approximately 11,000 per calendar day.
“This testing means something to our providers,” said James Crawford, MD, PhD, Northwell’s senior vice president of laboratory services, speaking of the situation in New York.
The nagging question, of course, is “but what?”
SARS-CoV-2 serology tests have provided valuable epidemiological information as the pandemic has progressed; helped in the diagnosis of multisystem inflammatory syndrome in children and adults; and remained critical in the evaluation of candidate, authorized, and approved vaccines. However, further work remains to determine the levels of antibody associated with protection against the virus.
“We can tell people, ‘You have this. This is how much antibody you have.’ But we are still working to understand what it means in regards to protection against infection or severe disease,” said Laura Gillim, PhD, technical director of science and technology and division director of infectious disease immunology at Labcorp.
This represents a potential opportunity. At Northwell and Labcorp, the data collected so far may be a staging ground for a new phase of SARS-CoV-2 serology research.
Pairing the Data: A Critical Path Forward
Northwell began antibody testing in April 2020, launching a voluntary serosurvey that involved 46,000 of its more than 70,000 employees to monitor their SARS-CoV-2 exposure. Northwell rapidly built up a capacity to test 10,000 samples daily, if needed, which it has maintained since. Testing opened to patients soon thereafter.
Labcorp rolled out five assays during 2020 and has built a diverse repertoire of serology tests. It stood up one of the largest testing capacities in the nation. Its research laboratories, meanwhile, have developed several of their own antibody tests, including one virus neutralization assay that has been used in numerous vaccine clinical trials.
The result—and the opportunity—for both Northwell and Labcorp has been large quantities of SARS-CoV-2-related serological data.
“We have this great data, we know it came from ‘John Smith’ in California, but we don’t know his clinical history or vaccination history,” Gillim said. “We don’t have that information, and that’s where the partnerships [come in]—to find some way to bring it all together.”
“Real-world data … is a way both to inform the medical science of the host response to this pathogen but also, hopefully, through linking it with clinical information, to make medical decisions in a reasonable way,” Crawford said.
Put another way, pairing serology data with virological, clinical, and demographic data may give scientists crucial information for determining what serology test results mean, such as what antibody levels represent protection and what immunity looks like.
Northwell is collaborating with Kaiser Permanente of Northern California on an effort to connect serology and clinical data, including vaccination history, Crawford said.
“Since the beginning of the pandemic, our priority has been to strategically deploy COVID-19 testing to support our region, especially for patients receiving health care. This has included antibody testing. Northwell’s strength is its real-world experience of what’s happening,” Crawford said.
Labcorp previously partnered with a state health system to build those connections on a smaller scale. The collaboration used a voluntary, cross-sectional serosurvey conducted statewide and included testing patients' SARS-CoV-2 antibody levels and collecting data on SARS-CoV-2 infection, COVID-19 vaccination status, and other underlying health conditions.
The key difference was the partners’ real-time data collection and analysis, rather than the retrospective approach that analyses of the existing collection of data would require. However, Labcorp’s prior partnership may provide helpful guidance on how to best approach an analyses of various data streams.
“I think we’re open to even more,” Gillim said.
It remains to be seen how efficiently the abundance of testing data can be combined with clinical data for analysis. Patient privacy and data security will continue to be a key area of focus for those involved in these studies.
But both Gillim and Crawford point out the necessity of making the attempt. As Northwell and Labcorp continue to accrue testing data, unity with clinical data may move the serology community one step closer to answering the “but what?”
These partnerships are key to fully leverage the potential of serology to inform public health recommendations and decisions.
“It’s being able to connect our lab data to outcomes. It’s partnering with a hospital or national health system,” Gillim said. “We’re confident this approach will help us find the answers we’re seeking.”