Evaluation of Neutralizing Antibodies against SARS-CoV-2 Variants after Infection and Vaccination Using a Multiplexed...

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• SARS-CoV-2 evolution necessitates updated methods to assess immune response durability against new variants.
• Current vaccines and antibody therapeutics may face challenges due to viral mutations.

Purpose of the Study:

• To develop and validate a multiplexed surrogate virus neutralization test (plex-sVNT) for evaluating antibody neutralization against multiple SARS-CoV-2 variants.
• To assess the durability of the immune response to SARS-CoV-2 variants in infected and vaccinated individuals.

Main Methods:

• Developed a plex-sVNT assay to simultaneously measure antibody neutralization against seven SARS-CoV-2 spike protein variants.
• Validated the plex-sVNT against the plaque reduction neutralization test (PRNT).
• Evaluated 170 samples from COVID-19 patients and 281 samples from individuals vaccinated with mRNA vaccines.

Main Results:

• The plex-sVNT showed >96% concordance with PRNT.
• Significantly reduced antibody neutralization activity against all SARS-CoV-2 variants compared to wild type was observed in both infected and vaccinated groups.
• Antibody neutralization activity declined within 5 months post-infection or vaccination, with a more pronounced decline in the vaccinated cohort.

Conclusions:

• The plex-sVNT is a reliable and convenient method for assessing antibody neutralization against SARS-CoV-2 variants.
• Reduced neutralization of variants and a decline in activity over time highlight the need for ongoing monitoring of COVID-19 immunity.
• The protective threshold of neutralizing antibody capacity against SARS-CoV-2 variants remains to be determined.