KYW Newsradio's Medical Reports are sponsored by Independence Blue Cross.
By Dr. Brian McDonough, Medical Editor
PHILADELPHIA (KYW Newsradio) — A viral blood test for COVID-19 is an oral or nasal swab or saliva test that looks for evidence of an active viral infection.
There are two major types: A PCR test and an antigen test.
PCR tests look for evidence of the virus genetic material, while antigen tests look for specific proteins on the virus surface.
Antigen tests produce results quickly but can be less sensitive, and reliability can be weak.
Viral tests don't tell if someone was infected in the past.





