NEW YORK ─ Siemens Healthineers said this week that it is developing a high-throughput antibody serology test for COVID-19 that can determine whether patients have had an immune reaction to SARS-CoV-2 coronavirus.
On the back of announcing a dip in its second quarter diagnostics revenues, the firm said that by the end of May it anticipates introducing an antibody test with a demonstrated sensitivity and specificity of more than 99 percent for use on its high-throughput analyzers.
Separately, the firm on Tuesday received US Food and Drug Administration Emergency Use Authorization for its Fast Track Diagnostics SARS-CoV-2 molecular test to detect COVID-19. The test received CE marking in April enabling its use in Europe.
Both the antibody diagnostic test and molecular diagnostic test have important roles to play in helping clinicians address the coronavirus pandemic, Deepak Nath, president of laboratory diagnostics at Siemens Healthineers, said in an interview.
"Just as it is extremely important to be able to conduct a molecular test that confirms the presence of an active infection, high performance, high-throughput serology testing is needed for several reasons," he said.
From a public health standpoint, the platforms will be valuable in helping clinicians establish disease prevalence, Nath said, adding, "To do that, you need to screen large groups of people and you need automated, high quality, highly accurate tests."
Further, for the development and introduction of COVID-19 vaccines, it is important to be able to assess the relative level of immune response in the body, something that can be achieved with high-throughput laboratory machines, but not with fingerstick antibody-based serology tests that provide a positive or negative result.
It is important to note, Nath said, that the presence of antibodies for detecting the immune response in the body does not mean the body has developed an immunity to COVID-19. "That has yet to be established for this virus, and studies are ongoing," he said. "However, to establish whether there is immunity, clinicians need high-throughput serology tests."
The firm's antibody-based serology platform detects both IgM and IgG antibodies, the two most important types of antibody responses to COVID-19 and other infectious diseases, he said.
The IgM antibody response occurs around four to five days after the virus can be detected in the blood, he said. Its response peaks at around nine days, and from nine to 28 days the IgM response goes away. The IgG antibody response is a more sustained response and is typically detectable 10 days to 14 days after viral material is detectable in the blood. The levels rise for around 28 days and then they start to level off, Nath said.
By the end of May, Siemens Healthineers anticipates shipping more than 25 million antibody-based serology tests for use on its Advia Centaur and Atellica immunoassay platforms, and the firm is developing an antibody-based serology assay for its Dimension Vista line of analyzers.
All told, the firm has an installed base of greater than 20,000 for the instruments that could run its antibody serology test, with 6,000 in North America, Nath said.
The three families of analyzers vary in the level of automation and throughput, he noted.
As a result, small, medium, and large hospitals and reference labs can select analyzers that best align with their testing volumes, and the analyzers can be connected if needed to scale up and satisfy a specific volume.
Assay designs have been completed for all three platforms and Siemens Healthineers is now scaling up production, Nath said. The antibody assay for the Dimension Vista platform is about two to three weeks behind that for the Advia Centaur and Atellica platforms.
The company has completed the development of the assays and is going through additional testing of antibodies it has produced before releasing its assays to the market, Nath said.
He said the firm is in discussions with the FDA about obtaining Emergency Use Authorization for its antibody serology tests across its three platforms and anticipates obtaining CE marking enabling its use in European countries and others that accept the designation.
With a level of sensitivity and specificity greater than 99 percent, Siemens expects its laboratory-based antibody test will exceed the FDA's stringent quality guidelines.
The FDA on Monday had issued new guidance that refines its stance on serology testing during the COVID-19 pandemic, telling antibody test developers they will no longer be allowed to simply notify the agency, but instead must file for an EUA and meet certain performance thresholds.
"We hold ourselves to a standard that is at least as high as what the FDA and other regulatory bodies expect," Nath said. Siemens antibody coronavirus assays have been developed using a quality system and processes that it has used to develop more than 200 antibody assays that have received regulatory clearances and are already in use, he said.
It is important to note, Nath said, that there are different types of serology assays, and the high throughput systems from the largest diagnostic manufacturers are the most accurate, including high-throughput immunoassay platforms developed by companies such as Roche, Abbott, Danaher's Beckman Coulter, and Ortho Clinical Diagnostics.
Assays that operate from a fingerstick of blood and often use point-of-care lateral flow technology are the least sensitive, he said. Clinicians also use ELISA platforms to run antibody tests, and research universities and other organizations developing laboratory tests frequently use this technology, but the technology is not "amenable to high levels of automation," Nath said.
"We have a long track record of developing assays not only for infectious diseases, but for a variety of conditions, including cardiovascular, metabolic, and others," Nath said. "Robust and well-established quality control processes govern every step of the way from design to development, verification and validation to manufacturing scale-up, and post-manufacturing."