Evaluation of three chemiluminescence immunoassay for the detection of SARS-CoV-2 antibody after BNT162b2 mRNA COVID-19 vaccine

ABSTRACT

Background: Vaccination programs have been highly effective for curbing the spread of SARS-CoV-2 . In this context, serology surveillance of SARS-CoV-2 antibodies represents a useful tool for monitoring of potential protective immunity in the population but the long-term antibody response over time remains an open question. Method(s) We compared the performance of three SARS-CoV-2 antibody serological immunoassays in 600 vaccinated individuals after two and third BNT162b2 mRNA COVID-19 (Comirnaty) vaccine dose. Result(s) All three methods were able to detect a post-vaccine humoral immune response with good analytical performance obtained from a comparison with serum samples obtained in the pre-Covid-19 era. Median (IQR) anti-RBD IgG, Access SARS-CoV-2 IgG (1st IS) and Access SARS-CoV-2 IgG II levels of the subjects investigated were, respectively, 687 BAU/mL (131-2325), 419 IU/ mL (58-1091) and 104 AU/mL (14-274). The analysis of the comparison of the methods showed a correlation between the levels of antibodies of the three methods analized. We also considered the kinetics of subjects with multiple doses and observed that the differences between the absolute decreasing gradients were statistically significant (overall Friedman test p <0.001). Conclusion(s) All immunoassays considered in the study proved useful in evaluating the antibody response to the vaccine. Our results suggest that postvaccination testing of antibody response is an important and feasible tool for following people after vaccination and selecting individuals who might require a third / fourth dose of vaccine at an earlier time point or subjects who may not need to another dose of vaccine due to previous SARS-CoV-2 infection. Reference Lo Sasso B. et al. Longitudinal analysis of anti-SARS-CoV-2 S-RBD IgG antibodies before and after the third dose of the BNT162b2 vaccine. Sci Rep. 2022;12 8679. Published online 2022 May 23.