Reconciliation of titer differences between SARS-CoV-2 neutralizing antibody assays.

Eva Stadler, Francesca Mordant, Matthew Gartner, Steffen S Docken, Miles P Davenport, David S Khoury, Kanta Subbarao

Abstract read

In one paragraph

Article in Journal of virology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it

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0citing papers in PubMed

–field-weighted citation impact

1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

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0 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Eva Stadler *Infection Analytics Program, Kirby Institute, UNSW Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-5129-8180

Francesca Mordant *Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Parkville, Melbourne, Victoria, Australia.ORCID 0000-0002-3754-2642

Matthew GartnerDepartment of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Parkville, Melbourne, Victoria, Australia.

Steffen S DockenInfection Analytics Program, Kirby Institute, UNSW Sydney, Sydney, New South Wales, Australia.ORCID 0000-0003-3771-5504

Miles P Davenport *Infection Analytics Program, Kirby Institute, UNSW Sydney, Sydney, New South Wales, Australia.

David S Khoury *Infection Analytics Program, Kirby Institute, UNSW Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-2663-1551

Kanta Subbarao *Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Parkville, Melbourne, Victoria, Australia.ORCID 0000-0003-1713-3056

Funding

NIH HHS HHSN272201400005C

6 · The paper itself

Abstract

SARS-CoV-2 antibody neutralization is a correlate of protection for COVID-19 and has been used to guide public health decisions. However, there is no standard neutralization assay, and absolute titers differ between assays. To investigate mechanisms causing these absolute titer differences, we compared 28 samples with three assays: a live virus cytopathic effect (CPE)-based microneutralization assay, a live virus focus reduction (immunospot, IS) assay, and a pseudotyped virus luciferase expression reduction (pseudovirus, PV) assay. We found significant correlations between all assays (ρ > 0.95 and IMPORTANCE: Protection against COVID-19 is related to how well serum antibodies neutralize SARS-CoV-2. This neutralization can be assessed using different assays, which often provide significantly different estimates. To better understand why assay results vary, we compared three commonly used types of neutralization assay. We found both strong correlations and significant differences in measured neutralization between the different assays. Differences in the type of virus (live SARS-CoV-2 virus compared to a pseudotyped virus with SARS-CoV-2 spike protein), how long cells, virus, and antibody were allowed to interact, and whether neutralization of a batch of virions ("per well" neutralization) or individual infectious virions ("per virion") was measured, all impacted virus neutralization. Understanding which factors have the largest impact on the differences between neutralization assays is an important first step toward harmonization of neutralization assays across the field.

Indexed as

Antibodies, NeutralizingAntibodies, ViralCOVID-19Neutralization TestsSARS-CoV-2AnimalsChlorocebus aethiopsHumansVero CellsAntibodies, NeutralizingAntibodies, Viralassay differencesmicroneutralizationneutralizationplaque-reduction assaypseudovirusSARS-CoV-2

Identifiers

PMID42657887

DOI10.1128/jvi.00823-26

PMCPMC13595964

What OpenQuestion holds

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.