What you need to know about antibody tests and the coronavirus pandemic

As the world watches and wonders when coronavirus pandemic stay-at-home orders and social distancing measures might end, some hope antibody tests might help provide a solution.

Antibody tests — also known as serology tests — aren’t meant to diagnose active infection with the coronavirus. Rather, they check for proteins in the immune system, known as antibodies, through a blood sample.

Their presence means a person was exposed to the virus and developed antibodies against it, which may mean they have at least some immunity — although experts are not sure how strong the immunity may be or even how long it will last.

In contrast, diagnostic testing, so far, has mostly used a laboratory technique known as a polymerase chain reaction (PCR) test. These tests can diagnose active infections through a sample — usually from a nose swab — that is then tested for viral genetic material.