Study flow diagram.

<p>Xpert stool testing of 0.6g and 1.2g volume from Xpert induced sputum (IS) and gastric washing (GW) results was performed on above recruited participants. As indicated, repeat testing was performed on a limited stool number of samples that were initially negative.</p

Sensitivity and specificity of Xpert stool assay as tested with pediatric clinical samples.

<p>Sensitivity and specificity of Xpert stool assay as tested with pediatric clinical samples.</p

Study flow diagram.

<p>Xpert stool testing of 0.6g and 1.2g volume from Xpert induced sputum (IS) and gastric washing (GW) results was performed on above recruited participants. As indicated, repeat testing was performed on a limited stool number of samples that were initially negative.</p

Analytical limit of detection.

<p><b>A.</b> BCG and <b>B.</b> <i>M</i>. <i>tuberculosis</i> H37Rv (MTB) was spiked into stool at final concentrations of 10 CFU/g through 10⁵ CFU/g, processed according to our protocol, and tested using the Xpert MTB/RIF assay.</p

DataSheet_1_Low pre-existing endemic human coronavirus (HCoV-NL63)-specific T cell frequencies are associated with impaired SARS-CoV-2-specific T cell responses in people living with HIV.pdf

BackgroundUnderstanding how HIV affects SARS-CoV-2 immunity is crucial for managing COVID-19 in sub-Saharan populations due to frequent coinfections. Our previous research showed that unsuppressed HIV is associated with weaker immune responses to SARS-CoV-2, but the underlying mechanisms are unclear. We investigated how pre-existing T cell immunity against an endemic human coronavirus HCoV-NL63 impacts SARS-CoV-2 T cell responses in people living with HIV (PLWH) compared to uninfected individuals, and how HIV-related T cell dysfunction influences responses to SARS-CoV-2 variants.MethodsWe used flow cytometry to measure T cell responses following PBMC stimulation with peptide pools representing beta, delta, wild-type, and HCoV-NL63 spike proteins. Luminex bead assay was used to measure circulating plasma chemokine and cytokine levels. ELISA and MSD V-PLEX COVID-19 Serology and ACE2 Neutralization assays were used to measure humoral responses.ResultsRegardless of HIV status, we found a strong positive correlation between responses to HCoV-NL63 and SARS-CoV-2. However, PLWH exhibited weaker CD4+ T cell responses to both HCoV-NL63 and SARS-CoV-2 than HIV-uninfected individuals. PLWH also had higher proportions of functionally exhausted (PD-1high) CD4+ T cells producing fewer proinflammatory cytokines (IFNγ and TNFα) and had elevated plasma IL-2 and IL-12(p70) levels compared to HIV-uninfected individuals. HIV status didn’t significantly affect IgG antibody levels against SARS-CoV-2 antigens or ACE2 binding inhibition activity.ConclusionOur results indicate that the decrease in SARS-CoV-2 specific T cell responses in PLWH may be attributable to reduced frequencies of pre-existing cross-reactive responses. However, HIV infection minimally affected the quality and magnitude of humoral responses, and this could explain why the risk of severe COVID-19 in PLWH is highly heterogeneous.</p