The U.S. Food and Drug Administration, together with the National Institutes of Health's National Cancer Institute, the Centers for Disease Control and Prevention, and the Biomedical Advanced Research and Development Authority, have been independently evaluating serology tests that detect the presence of antibodies against SARS-CoV-2, the novel coronavirus that causes COVID-19. The post-recovery tests will be especially helpful for people who think they had COVID-19 but weren't able to get a diagnostic test for the virus while they were infected.

Last month, the agencies released data on over a dozen antibody tests, and now they've followed up with data from five additional tests, including three that are no longer being sold in the U.S.

Gloved hand holding a vial marked positive for COVID-19

Image source: Getty Images.

One of the tests in the recent batch that still has an emergency use authorization, Healgen's COVID-19 IgG/IgM Rapid Test Cassette, scored quite high with a sensitivity -- the ability to detect a true positive case -- of 100% and a specificity -- the ability to detect a true negative -- of 97.5%. That's comparable to Abbott Labs' (NYSE:ABT) Architect SARS-CoV-2 IgG, which registered a sensitivity of 100% and a specificity of 99.6% in the previous round of testing.

The PerkinElmer (NYSE:PKI) EUROIMMUN SARS-CoV-2 ELISA (IgG) test wasn't quite as good, with a sensitivity of 90% and a specificity of 100%. While the results aren't competitive with the best tests, PerkinElmer's test can certainly find a place on the market, where demand outstrips supply. Bio-Rad Laboratories' (NYSE:BIO) Platelia SARS-CoV-2 Total Ab, for instance, has a sensitivity of 92.2% and a specificity of 99.6%.

The evaluations, which were run in April, also included three tests that are no longer on the market. Biomedomics and Phamatech voluntarily withdrew their tests, while Tianjin Beroni Biotechnology's test was removed from the market.

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