This procedure is also described in detail in the article by Omma et al. [10 (link)]. Briefly, a fully automated two-step sandwich immunoassay, using indirect chemiluminescent technology, was performed to measure anti-spike IgG levels (Atellica IM sCOVG Assay, Siemens Healthineers, Erlangen, Germany). There is a direct relationship between the amount of circulating SARS-CoV-2 IgG antibody and the amount of relative light units detected by the system. The analytical assay range of 0.50–150.00 index is reported as nonreactive (<1.00 index) or reactive (≥1.00 index).
While SARS-CoV-2 PCR tests were performed at each center, anti-spike protein IgG test was performed at the Ankara City Hospital Medical Microbiology Clinic Laboratory. SARS-CoV-2 neutralizing antibody tests were conducted in the National Virology Reference Laboratory of the Turkish Ministry of Health, General Directorate of Public Health.
While SARS-CoV-2 PCR tests were performed at each center, anti-spike protein IgG test was performed at the Ankara City Hospital Medical Microbiology Clinic Laboratory. SARS-CoV-2 neutralizing antibody tests were conducted in the National Virology Reference Laboratory of the Turkish Ministry of Health, General Directorate of Public Health.