# Population-Based Viral Antibody Profiles of Preschool Children in Burkina Faso

## TL;DR

This study examines antibody responses to multiple viruses in preschool children in Burkina Faso, finding no major impact of the SARS-CoV-2 pandemic on responses to RSV or poliovirus.

## Contribution

The study provides population-based viral antibody profiles in preschool children using a novel programmable phage immunoprecipitation and sequencing method.

## Key findings

- Sero-reactivity to SARS-CoV-2 was negatively correlated with age in months.
- No significant changes in RSV or poliovirus 1 antibody responses were observed after the SARS-CoV-2 pandemic.
- Azithromycin mass drug administration did not significantly affect antibody responses to SARS-CoV-2 or poliovirus 1.

## Abstract

Virus-associated infections remain a major burden of childhood morbidity and mortality in sub-Saharan Africa. This exploratory, population-based study used programmable phage immunoprecipitation and sequencing to simultaneously evaluate the antibody response to multiple viruses in dried blood spots from 251 children aged 12 to 59 months who were previously enrolled in the Community Health with Azithromycin Treatment trial conducted in Burkina Faso from 2019 to 2023. Linear mixed effects models, with cluster as the random effect, were used to examine associations between viral antibody response and age, sex, time points (before and after the onset of the severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] pandemic), and azithromycin mass drug administration (MDA). Sero-reactivity to SARS-CoV-2 was negatively correlated with age in months (β coefficient: −1.43; 95% CI: −2.03 to −0.84; Padj <0.001), but not to sex (β coefficient: 4.63; 95% CI: −11.90 to 21.17; Padj = 0.58) or azithromycin MDA (β coefficient: −9.43; 95% CI: −27.56 to 8.71; Padj = 0.45). Immunoreactivity to the respiratory syncytial virus (RSV) did not appear to be altered after the emergence of SARS-CoV-2 (β coefficient: 39.26; 95% CI: −0.20 to 78.72; Padj = 0.31). In addition, no detectable differences in the sero-reactivity to poliovirus 1 were observed with azithromycin MDA (β coefficient: 17.86; 95% CI: −25.35 to 61.07; Padj = 0.82). Although an association was observed between sero-reactivity to SARS-CoV-2 and age, the emergence of SARS-CoV-2 did not appear to alter the antibody response of preschool children in Burkina Faso to RSV or poliovirus vaccine uptake. Longitudinal studies in other at-risk populations in sub-Saharan Africa may improve mechanistic understanding and preventive strategies to decrease childhood morbidity.