Comparison of five commercial anti-SARS-CoV-2 total antibodies and IgG immunoassays after vaccination with BNT162b2 mRNA

  • Elisa Danese
  • Martina Montagnana
  • Gian Luca Salvagno
  • Matteo Gelati
  • Denise Peserico
  • Laura Pighi
  • Simone De Nitto
  • Brandon M. Henry
  • Stefano Porru
  • Giuseppe Lippi
Keywords: Antibody response, BNT162b2 mRNA vaccination, IgG


Background. Since universal vaccinations represents the most effective strategy to mitigate coronavirus disease 2019 (COVID-19), baseline assessment and post-vaccine monitoring of anti-SARS-CoV-2 neutralizing antibodies are essential to vaccination programs. Therefore, this study aimed to compare data of five commercial anti-SARS-CoV-2 immunoassays after administration of BNT162b2 mRNA Covid-19 vaccine.

Methods. Venous blood was collected from three healthcare workers, receiving a double (30 μg) dose of Comirnaty, on the day of the first vaccine dose and then at fixed intervals for the following 2 months. Anti-SARS-CoV-2 neutralizing antibody response was assayed with Roche Total Ig anti-RBD, DiaSorin IgG anti-S1/S2, Beckman Coulter IgG anti-RBD, SNIBE IgG anti-RBD and Technogenetics IgG anti-N/S1.

Results. A total number of 45 samples were drawn at the end of the 2-month study period. The Spearman’s correlations of absolute anti-SARS-CoV-2 antibodies were always excellent (all p<0.001), comprised between 0.967-0.994. Satisfactory results were also observed when absolute anti-SARS-CoV-2 antibodies values of the five methods were compared with the mean consensus value, with correlations always higher than 0.979 (all p<0.001). The agreement of anti-SARS-CoV-2 antibodies positivity versus the consensus median positivity ranged between 0.764 and 1.000 (always p<0.001), but become always >0.900 after readjustment of one assay cutoff.

Conclusion. All the immunoassays evaluated in this study appear suitable for monitoring anti-SARS-CoV-2 neutralizing antibodies response in subjects undergoing mRNA COVID-19 vaccination.


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Original paper