Neutralizing IgG antibodies

Determination of neutralizing antibodies after vaccination


The publication by Eberhardt KE et al. (Evaluation of a new spike (S) protein based commercial immunoassay for the detection of anti-SARS-CoV-2 IgG, Microorganisms 2021 March 31; 9(4):733) proves that our IDK® anti-SARS-CoV-2 IgG ELISA (K 5004) achieves the highest sensitivity among S-protein based assays in the detection of anti-SARS-CoV-2 IgG antibodies after COVID-19 recovery. The assay correlates better with neutralization than the competition and detects even the lowest concentrations of neutralizing antibodies. In addition, internal validation studies have shown that the test is excellent for detecting an immune response after COVID-19 vaccination. Therefore, the IDK® anti-SARS-CoV-2 IgG ELISA is ideally suited for the quantitative detection of neutralizing antibodies after COVID-19 vaccination.

A research group from France determined which antibody levels were protective after COVID-19 vaccination in nearly 9,000 healthcare workers:

  • Antibody level 13-141 BAU/mL: 12% protective against SARS-CoV-2
  • Antibody level 141-1700 BAU/mL: 89.3% protective against SARS-CoV-2
  • Antibody level > 1700 BAU/mL: 100% protective against SARS-CoV-2

Dimeglio C, Herin F, Martin-Blondel G et al. Antibody titers and protection against a SARS-CoV-2 infection. J Infect. 2021 Sep 21:S0163-4453(21)00483-7.