What you need to know:
Positive antibodies show evidence of previous exposure to SARS-CoV-2 virus
Antibody testing should be undertaken at least two weeks after onset of symptoms
The sensitivity and specificity of antibody tests vary over time and results should be interpreted in the context of clinical history
Antibody testing might have a useful role in diagnosing covid-19 in patients with late presentation, prolonged symptoms, or negative results from reverse transcription polymerase chain reaction tests
Evidence is currently insufficient to know whether individuals with SARS-CoV-2 antibodies have protective immunity
Read more: https://www.bmj.com/content/370/bmj.m3325