https://www.citymd.com/spike-protein-antibody-blood-test-faq

What is the Spike Protein Antibody test?

- A test for antibodies made against the spike protein of the COVID-19 virus.

What is the difference between the IgG Antibody test and the Spike Protein Antibody test?

- IgG COVID-19 Antibody (Blood Test):

- This was the first antibody test developed for COVID-19 – it potentially identifies antibodies created by you in response to an infection in order to fight the COVID-19 virus. It does NOT test for antibodies made in response to COVID-19 vaccination.

- Spike Protein COVID-19 Antibody (Blood Test):

- This test potentially identifies antibodies created by you in response to vaccination against the COVID-19 virus. It can also detect antibodies made in response to a COVID-19 infection.

What does the Spike Protein Antibody test detect?

- The body makes a class of proteins called antibodies which bind to organisms (i.e. COVID-19 virus) in order to fight off infection. Our bodies make multiple different antibodies which bind selectively to various components of the COVID-19 virus. We now have blood tests to detect two of these distinct antibodies, one of which is the Spike Protein antibody.