Abbott (NYSE:ABT) today highlighted University of Washington research showing that its COVID-19 blood antibody test had 99.9% specificity and 100% sensitivity among people tested 17 days after the start of symptoms.
Abbott has already shipped more than 10 million of the SARS-CoV-2 IgG lab-based serology blood tests around the world for use on the company’s Architect instruments. The company has secured an FDA EUA in the U.S. and CE Mark in the EU for the tests.
Proving test accuracy and receiving stamps of approval from regulatory agencies has become an important issue surrounding coronavirus antibody tests, which public officials generally view as important tools to reopen their economies after the pandemic’s first wave. The tests can provide insights into the percentage of the population that has been infected, recovered and hopefully gained some immunity — but only if they are accurate.
Accuracy concerns, including from the American Medical Association, caused FDA to tighten oversight of antibody tests early this week.
“Health systems will play a critical role in large scale testing, and collaboration with leaders such as the University of Washington helps to ensure that our tests are performing at the highest standards when they are used in real-world settings,” Abbott CE) Robert B. Ford said in a news release. “We want to do our part in providing hospitals and reference labs around the world with access to reliable antibody testing.”
The University of Washington research, published in the Journal of Clinical Microbiology, included the testing of 1,020 serum specimens collected prior to SARS-CoV-2 circulation in the United States. There was only one false positive — indicating a specificity of 99.9%
There were 125 patients who had already tested RT-PCR positive for SARS-CoV-2 — with 689 excess serum specimens available. After running the Abbott assay on the 689 specimens, there was 100% sensitivity (ability to exclude false negatives) at 17 days or more after symptoms began.
The research also involved running the Abbott tests on samples from 4,856 people in Boise, Idaho, collected over one week in April as part of the Crush the Curve initiative. The testing detected 87 positives for a positivity rate of 1.79%.