Understanding your spike protein antibody (blood test) results

Your Spike Protein Antibody results will be reported as a reference range:

>/= 0.80 U/mL: This is a positive result for anti-SARS CoV-2S. A positive result means your body’s immune system has generated a response to the COVID-19 vaccine. It may also mean your body’s immune system has generated a response to a prior COVID-19 infection. The test is not able to differentiate whether the antibodies produced were in response to the vaccine or to a prior infection. 

< 0.80 U/mL: This is a negative result for anti SARS CoV-2S. A negative result means your immune system has not generated a measurable response to the COVID-19 vaccination and that you have likely not had the COVID-19 infection. 

It is yet undetermined what Antibody level is correlated to immunity against developing the COVID-19 infection

Please note: A numerical value will be reported up to 2,500 U/mL. For patients testing higher then 2,500 U/mL, your results will be reported as “Greater Than 2,500 U/mL."

Negative: You tested negative for COVID-19 IgG antibody. This means you have not been infected with COVID-19. Please note, it may take 14-21 days to produce detectable levels of IgG following infection. If you had symptoms consistent with COVID-19 within the past 3 weeks and tested negative, repeat testing in 1-2 weeks may yield a positive result.

Equivocal: Your test results could not be interpreted as Positive or Negative. The most common reasons for equivocal results are presence of an immune response but unclear if against the infection being tested for (COVID-19 in this case) or similar infections (the common cold is a type of coronavirus). If indicated, a repeat test may yield more reliable results.