Evidence map›Paper›PMID 41784399›Full record

ArticleThe Journal of infectious diseases2026

Anti-spike IgG Avidity Enhances Neutralization of Severe Acute Respiratory Syndrome Coronavirus 2: A Prospective Study of Primary Infections and Immunizations.

Visa Nurmi, Lea Hedman, Katariina Vapalahti, Jussi Hepojoki, Hasan Uğurlu, Rommel Iheozor-Ejiofor, Chanice Knight, Kalle Saksela, Anu Kantele, Klaus Hedman and 1 more

Abstract read
In one paragraph

Article in The Journal of infectious diseases, 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
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Visa NurmiDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0001-8052-5592
Lea HedmanDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
Katariina VapalahtiDepartment of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Jussi HepojokiDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0001-5699-214X
Hasan UğurluDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0002-3849-7847
Rommel Iheozor-EjioforDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0001-7654-5515
Chanice KnightNuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
Kalle SakselaDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0003-0827-122X
Anu KanteleDepartment of Infectious Diseases, Inflammation Centre, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Klaus HedmanDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0003-1779-7960
Olli VapalahtiDepartment of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.ORCID 0000-0003-2270-6824

Funding

EU Horizon VEO and DURABLEFinnish Foundation for Research on Viral DiseasesFinnish Society for Study of Infectious DiseasesFinnish Society of Sciences and LettersHelsinki University Hospital Research and Education FundJane and Aatos Erkko FoundationMagnus Ehrnrooth FoundationMedical Research in University HospitalsResearch Council of FinlandSakari Alhopuro FoundationSigrid Jusélius FoundationThe Medical Society of FinlandThe Medical Society of Finland)VTR-State Funding for
6 · The paper itself

Abstract

backgroundImmune protection against coronavirus disease 2019 (COVID-19) relies, along with cellular immunity, on anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. We studied the effect of IgG avidity, the average antibody binding strength, on anti-SARS-CoV-2 neutralizing antibodies (nAbs), often considered the hallmark of effective immunity. Prior studies estimating the significance of avidity for nAb-mediated immunity have been complicated by the fact that not only the quality but also the quantity of antibodies impacts the results. Here we provide means for quantifying the impact of IgG avidity on neutralization, irrespective of antibody titer.

methodsWe introduce for anti-SARS-CoV-2 spike protein (S) and nucleoprotein (N) antibodies, IgG avidity assays shown to be unaffected by the IgG concentration. Hospitalized (n = 14) and nonhospitalized (n = 14) COVID-19 patients and vaccinees (n = 20) of early 2020 were assayed for Wuhan S-IgM, S-IgA, S-IgG, and S-IgG avidity; Wuhan N-IgG and N-IgG avidity; and Wuhan, Beta, and Delta nAbs, to identify the factors contributing to neutralization efficiency.

resultsN-IgG avidity was superior to S-avidity in pinpointing the time of SARS-CoV-2 primary infection. Both Wuhan nAb and Delta nAb correlated, expectedly, with Wuhan S-IgG level (P < .0001 each). Wuhan S-IgG avidity intensified homologous (Wuhan; P = .001) but not significantly heterologous (Delta; P = .053) neutralization. Accordingly, along with postinfection time, the average neutralization efficiency of S-IgG molecules increased while their concentration decreased. Quantitatively, doubling of Wuhan S-IgG avidity, at constant S-IgG quantity, augmented Wuhan neutralization 1.58- to 1.68-fold.

conclusionsComprehensive serological profiles of early SARS-CoV-2 primary infections and immunizations provided a model showing that the antiviral neutralization potency is enhanced by anti-spike IgG avidity. The methodology presented is applicable widely beyond COVID-19.

Indexed as

Antibodies, NeutralizingAntibodies, ViralAntibody AffinityImmunoglobulin GSARS-CoV-2Spike Glycoprotein, CoronavirusCOVID-19COVID-19 VaccinesHumansNeutralization TestsPandemicsProspective StudiesAntibodies, NeutralizingAntibodies, ViralCOVID-19 VaccinesImmunoglobulin GSpike Glycoprotein, Coronavirusspike protein, SARS-CoV-2IgG avidityimmunologyinfectious diseasesneutralizing antibodySARS-CoV-2

Identifiers

PMID41784399
PMCPMC13271396

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.