In a comparative study conducted by Public Health England in partnership with Oxford University, Siemens Healthineers’ COVID-19 antibody test proved the most effective out of four tests evaluated.
The efficacy and sensitivity of antibody tests have been questioned since their introduction onto the market, with critics citing concerns that some of these tests could be unable to accurately detect the presences of SARS-CoV-2 antibodies in recovered COVID-19 patients.
To determine which tests were the most effective, Public Health England and a clinical research team from the University of Oxford and Oxford University Hospitals NHS Trust evaluated four tests, also known as immunoassays, currently available on the market.
That included Abbott’s SARS-CoV-2 Immunoassay, DiaSorin’s LIAISON SARSCoV-2 S1/S2 IgG, Roche’s Elecsys Anti-SARS-CoV-2, and Siemens’ SARS-CoV-2 Total (COV2T). The researchers performed the tests in line with the instructions given by each manufacturer, and for each test they calculated sensitivity and specificity.
The sensitivity and specificity values were compared to the performance target set by the UK Medicines and Healthcare products Regulatory Agency (MHRA) of 98% across both criteria.
The Healthineers test came out on top, with a sensitivity value of 98.1% and a specificity value of 99.9%, proving more effective than the assays from Abbott, Roche and Diasorin. It was also the only test to meet the target set by the MHRA across both specificity and sensitivity values, with the other three tests only meeting the specificity targets.
“The test targets both IgM and IgG antibodies, which allows for early identification of individuals infected with the virus who have developed an immune response, even if they were asymptomatic or never diagnosed with the disease,” said Deepak Nath, president of Siemens Healthineers Laboratory Diagnostics.
The tests were evaluated according to sensitivity using 536 samples from patients with laboratory-confirmed COVID-19, at least 20 days after they began to experience symptoms. On the specificity value, the test were evaluated on 994 pre-pandemic specimens from unique, healthy adult individuals.
Healthineers’ received emergency use authorisation from the US Food and Drug Administration (FDA) for its test in June, with the company reporting that in its own test data the assay demonstrated 100% sensitivity and 99.8% specificity.
The difference between the company’s reported data and the independent evaluation shows the continual need for regulatory agencies to carry out their own tests on a range of marketed assays. In fact, none of the tests evaluated in the UK’s study met the accuracy data submitted to the FDA by their respective companies.