Evaluation of the Diagnostic Performance of Two Automated SARS-CoV-2 Neutralization Immunoassays following Two Doses of mRNA, Adenoviral Vector, and Inactivated Whole-Virus Vaccinations in COVID-19 Naïve Subjects

• Published in: Microorganisms (Basel) Vol. 11; no. 5; p. 1187
• Main Authors: Csoma, Eszter, Nagy Koroknai, Ágnes, Sütő, Renáta, Szakács Szilágyi, Erika, Pócsi, Marianna, Nagy, Attila, Bíró, Klára, Kappelmayer, János, Nagy, Béla
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.04.2023; MDPI
• Subjects: Adenoviridae; Adenoviruses; Analysis; Antibodies; Automation; Control; Coronaviruses; COVID-19; COVID-19 disease; COVID-19 infection; COVID-19 vaccines; Deactivation; different vaccine types; Identification and classification; Immunization; Immunoassay; Immunoassays; Laboratories; Males; Medical technology; Messenger RNA; mRNA; mRNA vaccines; Neutralization; Neutralizing; neutralizing antibody; SARS-CoV-2; serology; seroprevalence; Severe acute respiratory syndrome coronavirus 2; Subgroups; vaccine; Vaccines; Viral diseases; Viruses; Hungary; China; COVID-19 disease; neutralizing antibody; SARS-CoV-2; vaccine; serology; different vaccine types
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms11051187

Background: Limited data are available on humoral responses determined by automated neutralization tests following the administration of the three different types of COVID-19 vaccinations. Thus, we here evaluated anti-SARS-CoV-2 neutralizing antibody titers via two different neutralization assays in comparison to total spike antibody levels. Methods: Healthy participants (n = 150) were enrolled into three subgroups who were tested 41 (22–65) days after their second dose of mRNA (BNT162b2/mRNA-1273), adenoviral vector (ChAdOx1/Gam-COVID-Vac) and inactivated whole-virus (BBIBP-CorV) vaccines, with no history or serologic evidence of prior SARS-CoV-2 infection. Neutralizing antibody (N-Ab) titers were analyzed on a Snibe Maglumi® 800 instrument and a Medcaptain Immu F6® Analyzer in parallel to anti-SARS-CoV-2 S total antibody (S-Ab) levels (Roche Elecsys® e602). Results: Subjects who were administered mRNA vaccines demonstrated significantly higher SARS-CoV-2 N-Ab and S-Ab levels compared to those who received adenoviral vector and inactivated whole-virus vaccinations (p < 0.0001). N-Ab titers determined by the two methods correlated with each other (r = 0.9608; p < 0.0001) and S-Ab levels (r = 0.9432 and r = 0.9324; p < 0.0001, respectively). Based on N-Ab values, a new optimal threshold of Roche S-Ab was calculated (166 BAU/mL) for discrimination of seropositivity showing an AUC value of 0.975 (p < 0.0001). Low post-vaccination N-Ab levels (median value of 0.25 μg/mL or 7.28 AU/mL) were measured in those participants (n = 8) who were infected by SARS-CoV-2 within 6 months after immunizations. Conclusion: Both SARS-CoV-2 N-Ab automated assays are effective to evaluate humoral responses after various COVID-19 vaccines