Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: (A) Longitudinal trajectories of serum IgG (top row) and mucosal IgA (bottom row) antibody responses against four RSV-B proteins (PreF, PostF, G, NP) over time. Individual participant trajectories are shown as thin lines with low opacity, colored by infection status: not infected (black), sero-detected infections (orange), and PCR-confirmed infections (green). (B) Mean fold-change in antibody titres between the first bleed (pre-epidemic baseline) and second bleed (post-epidemic) for serum IgG and mucosal IgA responses to RSV-B proteins. Bars represent mean fold-change (log10 scale) stratified by infection status, with error bars indicating standard error.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: (A) Post-infection longitudinal antibody titers for four viral RSV-B proteins (PreF, PostF, G, and NP) across different antibody types; serum IgG and mucosal IgA. Lines show the median posterior predictive fit from the fitted Bayesian model, and the points show the observational titre data, with the size correlating with the sample size for that bin. (B) Peak antibody (x axis) and persistence measured as duration above a 2-fold (left panel) and 4-fold titre rise (right panel) in days. Data points show median posterior values for measurements of four viral RSV-B proteins (PreF, PostF, G, and NP) across different antibody types: serum IgG and mucosal IgA.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: Serum IgG, top row; mucosal IgA, bottom row and columns are viral antigen target (PreF, PostF, G, and NP for both RSV-A and RSV-B strains). The solid green line represents the mean estimated probability of protection given exposure to infection as a function of antibody titre, with shaded ribbons indicating 95% credible intervals. Background histograms show the distribution of antibody titres at infection for infected individuals (orange) versus non-infected individuals (gray).

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: Model performance comparison across single biomarker models and the dual biomarker model, defined by out-of-sample predictive accuracy (LOO-ELPD, x-axis) and discrimination ability (area under the ROC curve, AUC, y-axis). Circles indicate serum IgG models, squares represent mucosal IgA models, and the triangle denotes the dual biomarker model combining serum IgG and mucosal IgA to RSV-B PreF. The best-performing model within each biomarker class is highlighted with darker shading. Error bars show the standard error of LOO-ELPD (horizontal) and 95% confidence intervals for AUC (vertical). The dashed horizontal line indicates an AUC of 0.7.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Comparison, Biomarker Discovery

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: (A) Longitudinal trajectories of serum IgG (top row) and mucosal IgA (bottom row) antibody responses against four RSV-B proteins (PreF, PostF, G, NP) over time. Individual participant trajectories are shown as thin lines with low opacity, colored by infection status: not infected (black), sero-detected infections (orange), and PCR-confirmed infections (green). (B) Mean fold-change in antibody titres between the first bleed (pre-epidemic baseline) and second bleed (post-epidemic) for serum IgG and mucosal IgA responses to RSV-B proteins. Bars represent mean fold-change (log10 scale) stratified by infection status, with error bars indicating standard error.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: (A) Post-infection longitudinal antibody titers for four viral RSV-B proteins (PreF, PostF, G, and NP) across different antibody types; serum IgG and mucosal IgA. Lines show the median posterior predictive fit from the fitted Bayesian model, and the points show the observational titre data, with the size correlating with the sample size for that bin. (B) Peak antibody (x axis) and persistence measured as duration above a 2-fold (left panel) and 4-fold titre rise (right panel) in days. Data points show median posterior values for measurements of four viral RSV-B proteins (PreF, PostF, G, and NP) across different antibody types: serum IgG and mucosal IgA.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: Serum IgG, top row; mucosal IgA, bottom row and columns are viral antigen target (PreF, PostF, G, and NP for both RSV-A and RSV-B strains). The solid green line represents the mean estimated probability of protection given exposure to infection as a function of antibody titre, with shaded ribbons indicating 95% credible intervals. Background histograms show the distribution of antibody titres at infection for infected individuals (orange) versus non-infected individuals (gray).

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: Model performance comparison across single biomarker models and the dual biomarker model, defined by out-of-sample predictive accuracy (LOO-ELPD, x-axis) and discrimination ability (area under the ROC curve, AUC, y-axis). Circles indicate serum IgG models, squares represent mucosal IgA models, and the triangle denotes the dual biomarker model combining serum IgG and mucosal IgA to RSV-B PreF. The best-performing model within each biomarker class is highlighted with darker shading. Error bars show the standard error of LOO-ELPD (horizontal) and 95% confidence intervals for AUC (vertical). The dashed horizontal line indicates an AUC of 0.7.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Comparison, Biomarker Discovery

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: A. Weekly incidence of PCR-confirmed RSV infections (stacked histogram) and cumulative attack rate (black line) among 342 household cohort participants from October 2022 to May 2023. Bars are colored by symptom status at detection: symptomatic (red, detected at unscheduled visits) or asymptomatic (blue, detected at scheduled home or clinic visits). B. Timeline of serological sampling for PCR-confirmed infected individuals. Each horizontal line represents one participant (ordered by date of PCR-confirmed infection), with grey tiles indicating bleed dates and colored circles marking the timing of PCR-confirmed infection (colored by symptom status as in panel a). C. Longitudinal trajectories of serum IgG (top row) and mucosal IgA (bottom row) antibody responses against four RSV-A proteins (PreF, PostF, G, NP) over time. Individual participant trajectories are shown as thin lines with low opacity, colored by infection status: not infected (black), serologically-defined infections (orange), and PCR-confirmed infections (green). D. Mean fold-change in antibody titres between the first bleed (pre-epidemic baseline) and second bleed (post-epidemic) for serum IgG and mucosal IgA responses to RSV-A proteins. Bars represent mean fold-change (log10 scale) stratified by infection status, with error bars indicating standard error.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Sampling, Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: A. Post-infection longitudinal antibody titers for four viral RSV-A proteins (PreF, PostF, G, and NP) across different antibody types; serum IgG and mucosal IgA. Lines show the median posterior predictive fit from the fitted Bayesian model, and the points show the observational titre data, with the size correlating with the sample size for that bin. B Peak antibody (x axis) and persistence measured as duration above a 2-fold (left panel) and 4-fold titre rise (right panel) in days. Data points show median posterior values for measurements of four viral RSV-A proteins (PreF, PostF, G, and NP) across different antibody types: serum IgG and mucosal IgA.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: Serum IgG, top row; mucosal IgA, bottom row and columns are viral antigen target (PreF, PostF, G, and NP for both RSV-A and RSV-B strains). The solid green line represents the mean estimated probability of protection given exposure to infection as a function of antibody titre, with shaded ribbons indicating 95% credible intervals. Background histograms show the distribution of antibody titres at infection for infected individuals (orange) versus non-infected individuals (gray).

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: A. Model performance comparison across single biomarker models and the dual biomarker model, defined by out-of-sample predictive accuracy (LOO-ELPD, x-axis) and discrimination ability (area under the ROC curve, AUC, y-axis). Circles indicate serum IgG models, squares represent mucosal IgA models, and the triangle denotes the dual biomarker model combining serum IgG and mucosal IgA to RSV-A PreF. The best-performing model within each biomarker class is highlighted with darker shading. Error bars show the standard error of LOO-ELPD (horizontal) and 95% confidence intervals for AUC (vertical). The dashed horizontal line indicates an AUC of 0.7. B. Summary of Pearson correlation coefficients for RSV-A protein antigens, comparing serum IgG (blue) and mucosal IgA (red) binding titres with neutralisation IC50 values. C. Counterfactual analysis comparing the increase in protection from boosting pre-infection antibody titres by 4-fold or 8-fold using either a single mucosal IgA biomarker model (purple) or a dual biomarker model combining mucosal IgA and serum IgG (blue). D. Two-dimensional protection surface for the dual biomarker model using serum IgG and mucosal IgA antibodies to RSV-A PreF. The continuous surface represents the predicted probability of protection given exposure as a function of both serum (x-axis) and mucosal (y-axis) antibody titres. Black contour lines delineate regions of constant protection probability at 50%, 70%, 80%, and 90%. Individual data points overlay the surface, with filled circles representing participants who were protected despite exposure and open circles representing those who became infected. Antibody titres are displayed on a log10 scale. E. Pearson correlation coefficients between RSV-A variant biomarkers at the time of infection. Color intensity represents correlation strength, ranging from blue (weak correlation) through white (no correlation) to green (strong positive correlation).

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Comparison, Biomarker Discovery, Binding Assay, Infection, Variant Assay

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: (A) Scatter plots showing serum IgG ELISA titres versus neutralization IC50 for all RSV-A variants. Filled circles indicate measurements above the limit of detection (LOD) and open circles indicating censored values below LOD (adjusted to LOD value). Linear regression lines with 95% confidence intervals are shown in blue. (B) Scatter plots showing mucosal IgA ELISA titres versus neutralization IC50 for all RSV-A variants following the same format as panel B.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Enzyme-linked Immunosorbent Assay, Neutralization

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: Top. shows the total number of inferred infections and infection type composition (PCR-confirmed in orange vs serologically-inferred in blue) for each model. Attack rates are shown in parentheses. Bottom. shows the combined performance ranking (average of AUC and LOO-ELPD ranks) for each RSV-A biomarker as a correlate of protection across the four models. Lower ranks (green) indicate better predictive performance, while higher ranks (red/orange) indicate poorer performance. Red boxes denote the top-ranked biomarker in each scenario.

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection, Biomarker Discovery

Journal: medRxiv

Article Title: Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting

doi: 10.64898/2026.03.16.26348479

Figure Lengend Snippet: (A) Baseline and peak antibody titres stratified by age group for serum IgG (left panel) and mucosal IgA (right panel) against four RSV-A antigens (PreF, PostF, G, NP). Gray squares represent baseline titres at the time of infection, colored circles represent peak titres post-infection, and gray lines connecting them indicate the magnitude of antibody boosting. Point are colored according to age groups. (B) Relationship between baseline antibody titre at infection (x-axis) and fold-rise in titre post-infection (y-axis), illustrating the antibody ceiling effect where individuals with higher pre-existing titres exhibit smaller relative boosts. Linear regression lines (solid) with 95% confidence intervals (shaded regions) demonstrate the negative relationship

Article Snippet: RSV antigens (RSV-A Pre-Fusion (ProteoGenix, product code: PX-P6126), RSV-B Pre-Fusion (SinoBiological, product code: 40832-V08B), RSV-A Post-Fusion (SinoBiological, product code: 11049-V08B), RSV-B Post-Fusion (SinoBiological, product code: 40999-V08H), RSV-A G protein (SinoBiological, product code: 11070-V08H2), RSV-B G protein (SinoBiological, product code: 13029-V08H, RSV-A Nucleoprotein (SinoBiological, product code: 40821-V08E and RSV-B Nucleoprotein (SinoBiological, product code: 40822-V08F)), were coupled to distinct bead regions.

Techniques: Infection