Antibody tests for Covid-19 wrong up to half the time, CDC says
(CNN) Antibody tests used to determine if people have been infected in the past with Covid-19 might be wrong up to half the time, the US Centers for Disease Control and Prevention said in new guidance posted on its website.
Antibody tests, often called serologic tests, look for evidence of an immune response to infection. “Antibodies in some persons can be detected within the first week of illness onset,” the CDC says.
They are not accurate enough to use to make important policy decisions, the CDC said.
“Serologic test results should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories, or correctional facilities,” the CDC says.
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This should ring a bell with Lyme/MSIDS patients.
- https://www.fda.gov/medical-devices/emergency-situations-medical-devices/eua-authorized-serology-test-performance FDA has summarized the expected performance of the tests it has authorized based on the information FDA reviewed when deciding whether or not to grant these tests an Emergency Use Authorization and assuming a prevalence of 5% for PPV and NPV calculations.