Diversity of immunization strongly impacts SARS-CoV-2 antibody function surrogates

Area of Science:

• Immunology
• Virology
• Vaccinology

Background:

• Humoral immune response evaluation is critical for understanding vaccine efficacy and infection outcomes.
• System serology provides a multi-parametric approach to comprehensively assess immune status.
• SARS-CoV-2 variants necessitate continuous evaluation of immune responses and vaccine effectiveness.

Purpose of the Study:

• To investigate the utility of system serology in deciphering humoral immunity following different SARS-CoV-2 immunization strategies.
• To identify key serological parameters that correlate with protection against SARS-CoV-2 infection and variants.
• To assess the role of Fc-dependent functions in the variability of immune responses.

Main Methods:

• Analysis of serum samples from 180 individuals across four distinct SARS-CoV-2 immunization history groups.
• Application of six different serological assays to evaluate multiple immune response parameters.
• Focus on Fc-dependent parameters and neutralizing antibody activity against SARS-CoV-2 antigens and variants.

Main Results:

• System serology effectively deciphers population immunity against SARS-CoV-2 antigens and variants.
• Fc-dependent parameters significantly contribute to the variability observed in humoral immune responses after different immunization schemes.
• Robust cross-reactive Fc-dependent effector functions are important for controlling viral replication, particularly when neutralizing antibodies show limited cross-reactivity.

Conclusions:

• System serology is an indispensable tool for a comprehensive understanding of SARS-CoV-2 immunity.
• Fc-dependent effector functions play a critical role in conferring protection against evolving SARS-CoV-2 variants.
• Continued evaluation using system serology is recommended to guide vaccination strategies, especially for vulnerable populations.