New government guidance is raising doubt about the accuracy of coronavirus antibody tests.
The CDC says the tests, used to determine if people have been infected in the past, could be wrong up to half the time.
It recommends they not be used to decide who returns to work.
This comes as two major testing companies, Quest Diagnostics and Labcorp, are rolling out expanded testing programs. In our collaboration with the journalism company "Clear Health Costs," CBS News Consumer Investigative Correspondent Anna Werner has been looking into those programs.
