Monoclonal Antibodies as SARS-CoV-2 Serology Standards: Experimental Validation and Broader Implications for Correlates of Protection

Published

October 28, 2023

Author(s)

Lili Wang, Paul Patrone, Anthony Kearsley, Jerilyn Izac, Adolfas Gaigalas, John Prostko, Hang Xie, Linhua Tian, Elzafir Elsheikh, Edward Kwee, Troy Kemp, Simon Jochum, Natalie Thornburg, Clifford McDonald, Adi Gundlapalli, Sheng Lin-Gibson

Abstract

COVID-19 has highlighted the need for more accurate and reproducible measurements of humoral immunity, including antibody levels and neutralization potential, which are critical for diagnostics, seroprevalence estimates, and development of vaccines and other therapies. Due to the large number of assay formats and reagents, these measurements are known to be highly variable with large uncertainties. The development of WHO international standard (WHO IS) has facilitated assay comparability through normalization to a common material, but the development process was arduous and lengthy, and cannot keep pace with the rapid emergence of new variants. Herein we present results from an interlaboratory study designed to address the following questions: 1) determine if a monoclonal antibody (mAb) can be used alone or with the WHO IS for assay harmonization and standardization, 2) understand the strengths and weaknesses of different neutralization assay formats, and 3) establish a more predictive method for correlates of protection. Using a new hierarchy of data analyses based on thermodynamics of antibody binding, we demonstrate that uncertainty reduction associated with harmonization does not meaningfully depend on the reference standard. Notably, both the theory and experimental data confirmed that mAbs and WHO IS performed identically as a primary standard for establishing traceability and bridging different serology assay platforms. A key aspect of our new analysis method is a precise, mathematical definition of harmonization that separates uncertainty due to sample-assay and reference-assay effects, enabling the quantitation of, and thus the removal of, sources of uncertainty. In addition, we compared sensitivity and specificity of three neutralization assay formats– bead-based surrogate assay, pseudovirus, and a live virus assay – and found pseudovirus neutralization assay to be the best at detecting neutralizing antibodies for the study. Finally, we propose a modeling framework that quantifies the probability of neutralization potential given a binding measurement. While approaches developed herein utilize COVID-19 as the use case, we expect the methods to be broadly applicable. The metrological anchoring of complex serological and neuralization assays and fast turn-around production of mAb reference control enable the comparability and traceability of serological assay results for new variants of SARS-CoV-2 and immune response to other viruses.

Citation

Nature Biotechnology

Pub Type

Journals

Download Paper

https://doi.org/10.3390/ ijms242115705

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Citation

Wang, L. , Patrone, P. , Kearsley, A. , Izac, J. , Gaigalas, A. , Prostko, J. , Xie, H. , Tian, L. , Elsheikh, E. , Kwee, E. , Kemp, T. , Jochum, S. , Thornburg, N. , McDonald, C. , Gundlapalli, A. and Lin-Gibson, S. (2023), Monoclonal Antibodies as SARS-CoV-2 Serology Standards: Experimental Validation and Broader Implications for Correlates of Protection, Nature Biotechnology, [online], https://doi.org/10.3390/ ijms242115705, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=936740 (Accessed December 22, 2024)