Antibody tests for Covid-19 wrong half the time, CDC says new guidance
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.
"Serologic test results should not be used to make
decisions about returning persons to the workplace."
