Comparison of four automated SARS-CoV-2 serological immunoassays in Lebanon

Automated immunoassays have been introduced to complement real time PCR (RT-PCR) in the battle against SARS-CoV-2. This study compares four serological automated immunoassays by different manufacturers (Abbott, Euroimmun, Roche and Snibe) that are available in Lebanon with regards to specificities, sensitivities, inter-agreement and positive/negative distinction abilities. One hundred and fifty-seven samples (73 with a positive RT-PCR and 84 controls) were analyzed. The 73 study samples were divided into 3 time categories: ≤ 7 days, 8-13 days and ≥ 14 days based on time since first positive RT-PCR or first symptoms. The category "total days" was studied as the average of all the three time categories. All assays had 100% specificity and their sensitivities in the "total days" category ranged from 75.3% to 20.6% (Snibe IgM). The sensitivity was low for all at ≤ 7 days and increased gradually in the other time categories. The IgG assays by different manufacturers showed high inter-agreement. The assays also showed good positive/negative discriminative abilities after 14 days. The four studied automated immunoassays (except for Snibe IgM) show an adequate diagnostic performance when used 14 days after first positive PCR or first symptom onset.