解释

https://www.questdiagnostics.com/home/Covid-19/HCP/antibody/

SARS-CoV-2 Antibody (IgG), Spike, Semi-Quantitative (test code 34499)
A SARS-CoV-2 semi-quantitative IgG test result is interpreted as a positive value at an index4,5 of ≥1.00. This positive result means that an individual has developed an immune response to recent/prior SARS-CoV-2 infection within the limit of detection of the assay.4,5,16,17

A negative semi-quantitative antibody result means that the patient serum specimen had no SARS-CoV-2 spike IgG antibodies, or that the relative level of antibodies in the patient specimen was below the index cutoff.4,5

• Estimated assay sensitivity is >99.9% for specimens collected at least 15 days post–symptom onset,4,5 based on positive percent agreement (PPA)1 of SARS-CoV-2 IgG serology results among SARS-CoV-2 RNA−positive patients4,5
• Estimated assay specificity is approximately 99.9%4,5 based on negative percent agreement (NPA)2 assessed by performing cross-reactivity studies utilizing serum specimens positive for antibodies to other respiratory viruses pre– and post–COVID-19 time periods4,5

 

这个检测适用于己知得了新冠的病人，或者查找某人是否得过新冠（但没确诊）。只要是阳性，即知得过。故数值大小高低不重要，只回答：是/否。

 

换句话说，这个检测不适于接种疫苗者观察跟踪抗体水平