Ethos Laboratories, Newport, Ky, and Genscript, Piscataway, NJ, have formed a partnership to offer the first quantitative surrogate viral neutralization test (sVNT) to evaluate covid-19 protective immunity in the United States. Marketed as Tru-Immune, the test will measure and quantify the neutralizing capacity of antibodies against SARS-CoV-2, the causative pathogen of covid-19.
The Tru-Immune test will identify patients with the most effective antibody response capable of inhibiting virus replication. Such information has not previously been available, and will pave the way for blood centers across the United States to recruit patients who have recovered from covid-19 and exhibit the greatest potential to inhibit the virus.
In a report published by Johns Hopkins University, the authors state that “neutralization assays are the gold standard for determining if a patient has effective antibodies and protective immunity against SARS-CoV-2. The ability of antibodies to prevent viral replication and clear infection is determined through neutralization assays.”1 Commercialization of the new serological test will assist government officials and medical authorities in determining population health immunity levels for reentry into the workforce, and will help to establish a ‘new normal’ for American society.
“Tru-Immune is the first test to evaluate protective immunity to the SARS-CoV-2 virus that does not require the use of live virus, cell culture, or even pseudovirus,” says Joshua Gunn, PhD, chief scientific officer at Ethos research and development. “These significant technical innovations allow us to process samples in less than 3 hours, whereas traditional viral neutralization tests can take 3 to 5 days to produce results. Serological assays capable of detecting anti-SARS-CoV-2 antibodies have flooded the market but are not capable of measuring the viral neutralizing capacity of these antibodies.”
Tests that are ‘prefabricated’ to detect IgA, IgG, and IgM antibodies can have limited sensitivity. By contrast, the Tru-Immune test is expected to detect all antibody-neutralizing capacity, and to provide quantitative data about how effective any existing antibodies are at preventing the virus from interacting with its cellular target.
If Tru-Immune test results indicate the presence of neutralizing antibodies, then the patient has been exposed and his or her immune system is capable of inhibiting the virus if exposed again. Longitudinal studies and serial testing will be required to better understand how long the protective antibody response lasts in recovered patients, and this information will be key for developing effective vaccine strategies.
“This test was validated using PCR-confirmed positive control samples, and exhibited sensitivity and specificity of 100%,” says Todd Bladel, chief operating officer at Ethos Laboratories. “Tru-Immune will provide a level of actionable data that has not been previously available. We feel strongly that this novel test will play a central role in the penultimate chapter of covid-19 by providing quantitative information about protective immunity, aiding vaccine development, and guiding patient selection for convalescent plasma therapies to treat the critically ill.”
For more information, visit TruImmune.
Reference
1. Gronvall G, Connell N, Kobokovich A, et al. Developing a National Strategy for Serology (Antibody Testing) in the United States. Baltimore: Johns Hopkins Center for Health Security, 2020. Available at https://bit.ly/3emQVfv. Accessed June 22, 2020.
