It is still not clear whether detection of COVID-19 antibodies translates to long-term immunity to the virus.
The US Food and Drug Administration (FDA) on Wednesday granted Emergency Use Authorization (EUA) for 2 new tests that can detect antibodies to SARS-CoV-2 (COVID-19), while Abbott Laboratories announced the launch of its own serology test.
The approvals were granted to Chembio Diagnostic Systems for its DPP COVID-19 System, and to Ortho Clinical Diagnostics for its VITROS® Immunodiagnostic Products Anti-SARS-CoV-2 Total Reagent Pack and Calibrators. These 2 tools join Cellex's antibody test, which was approved via EUA earlier this month.
Although there is some debate over the timeline of antibody detection, the FDA determined that the benefits outweigh the risks of potential false positives or negatives.
Chembio's serological point-of-care test can provide numerical readings for both IgM and IgG levels within 15 minutes from a simple finger stick drop of blood.
Ortho's detects antibodies (including IgG and IgM) and runs with a system that can process approximately 150 tests in an hour.
"Antibody serology (blood based) tests can identify individuals who have developed an immune response to the SARS-CoV-2 virus," Ortho said in a statement. "These tests can aid in diagnosing symptomatic or asymptomatic individuals of acute infection together with molecular tests or clinical information. They also can identify individuals who have previously been infected with the SARS-CoV-2 virus and recovered."
Meanwhile, Abbott is launching its serology test as part of an FDA agency process that allows companies to produce and market tests without an explicit EUA, although the company says it plans to file for one.
"We're significantly scaling up our manufacturing for antibody testing and expect to ship close to 1 million tests to US customers this week and 4 million of the antibody tests during April," Abbott said in its statement.
Antibody tests like these could help identify individuals who were either infected with COVID-19 but never diagnosed, or who had mild symptoms, or who were asymptomatic entirely, according to Florian Krammer, PhD, professor of microbiology at the Icahn School of Medicine at Mount Sinai Health System.
"It has a lot of uses in research. We can use it to better understand the antibody response and the dynamics," Krammer, whose microbiology lab is developing a serological assay for SARS-CoV-2, told Contagion®. "We can now perform serosurveys to figure out how widespread spread the virus actually is. People who might not have symptoms might still produce an immune response."