New research supports clinical utility of Labcorp’s COVID-19 antibody testing
Throughout the COVID-19 pandemic, experts have been working to understand the body’s immune response to SARS-CoV-2, the virus that causes COVID-19 infection. Currently, the CDC does not recommend COVID-19 antibody testing to assess immunity following vaccination or the need for vaccination in those who are unvaccinated.
However, there may still be clinical value in using serology testing to measure the risk of COVID-related complications, particularly for immunocompromised populations, whose antibody responses (or lack thereof) may make them more vulnerable to severe COVID-19 infections. According to the CDC, immunocompromised individuals hospitalized with COVID-19 have accounted for over 12% of all hospitalized COVID-19 infections, while representing less than 3% of the general population.
Now, in a new retrospective cohort study, researchers examined the association between COVID-19 antibody levels and different clinical outcomes, in an effort to better understand not just the immune response to SARS-CoV-2, but also what a patient’s antibody levels can tell us about their risk of subsequent COVID-related complications.
Exploring the associations between COVID-19 antibodies and health outcomes
In the study, researchers looked at laboratory data containing COVID-19 antibody testing results from both Labcorp and Quest, as well as linked medical and pharmacy claims data, between November 2020 and December 2021.
Of the 195,446 individuals included in the study’s cohort, over 73% had detectable levels of COVID-19 antibodies, with fewer than 30% showing non-detectable antibody levels. Having an immunocompromising medical condition seemed to affect individuals’ antibody levels in the study; immunocompromised conditions were present in 7% and 45.9% of the cohort, respectively.
In the overall population, having detectable versus non-detectable antibodies was associated with an estimated 44% relative reduction in subsequent COVID-19 infection risk and an 80% relative reduction in the risk of serious health outcomes. Researchers also saw relative risk reductions among immunocompromised individuals in the study.
According to the study authors, these results may support the use of COVID-19 serology testing in counseling immunocompromised populations and other high-risk individuals about serious health outcomes and appropriate ways to mitigate risk.
What else can antibody testing tell us about COVID-19 risk?
As healthcare providers evaluate patients’ COVID-19 risk in a post-pandemic world, it’s important to know what value antibody testing may hold, especially for immunocompromised individuals.
In addition to this study, other data have shown that, when patient samples are analyzed with Labcorp’s antibody test, higher levels of antibodies correlated with higher levels of neutralizing antibodies—which, in turn, have been associated with increased protection from infection, reinfection and severe disease.\
While there is still much to learn about the clinical utility of COVID-19 antibody testing, new studies are helping us find more answers every day.