Divergence of wastewater SARS-CoV-2 and reported laboratory-confirmed COVID-19 incident case data coincident with wide-spread availability of at-home COVID-19 antigen tests

PeerJ, Journal Year: 2023, Volume and Issue: 11, P. e15631 - e15631

Published: June 27, 2023

Concentrations of SARS-CoV-2 RNA in wastewater settled solids from publicly owned treatment works (POTWs) historically correlated strongly with laboratory confirmed incident COVID-19 case data. With the increased availability at-home antigen tests since late 2021 and early 2022, test seeking behavior has decreased. In United States, results are not typically reportable to public health agencies thus counted reports. As a result, number reported laboratory-confirmed cases decreased dramatically, even during times positivity rates concentrations RNA. Herein, we tested whether correlative relationship between incidence rate changed 1 May point time immediately before onset BA.2/BA.5 surge, first surge begin after was high region. We used daily data three POTWs Greater San Francisco Bay Area California, USA for analysis. found that although there is significant positive association measurements collected parameters describing different than those prior 2022. If or continues change, will continue change. Our suggest, assuming shedding remains relatively stable among infected virus as variants emerge, can be estimate they would have been when testing were at (here, 2022) using historical

Language: Английский

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An intranasal vaccine comprising SARS-CoV-2 spike receptor-binding domain protein entrapped in mannose-conjugated chitosan nanoparticle provides protection in hamsters

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: July 26, 2023

Abstract We developed a novel intranasal SARS-CoV-2 subunit vaccine called NARUVAX-C19/Nano based on the spike protein receptor-binding domain (RBD) entrapped in mannose-conjugated chitosan nanoparticles (NP). A toll-like receptor 9 agonist, CpG55.2, was also added as an adjuvant to see if this would potentiate cellular immune response NP vaccine. The assessed for immunogenicity, protective efficacy, and ability prevent virus transmission from vaccinated animals naive cage-mates. results were compared with RBD mixed alum administered intramuscularly. BALB/c mice twice intranasally vaccines exhibited secretory IgA pronounced Th1-cell response, not seen intramuscular alum-adjuvanted protected Syrian hamsters against wild-type infection challenge indicated by significant reductions weight loss, lung viral load pathology. However, despite significantly reduced nasal turbinates oropharyngeal swabs NP-vaccinated hamsters, prevented naïve In conclusion, RBD-based formulations induced mucosal mediated responses but transmission.

Language: Английский

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Viral kinetics of sequential SARS-CoV-2 infections

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 5, 2023

Abstract The impact of a prior SARS-CoV-2 infection on the progression subsequent infections has been unclear. Using convenience sample 94,812 longitudinal RT-qPCR measurements from anterior nares and oropharyngeal swabs, we identified 71 individuals with two well-sampled between March 11 th , 2020, July 28 2022. We compared viral kinetics first vs . second in this group, adjusting for variant, vaccination status, age. Relative to infections, usually featured faster clearance time. Furthermore, person’s relative (rank-order) time, others infected same was roughly conserved across so that who had relatively fast time their also tended have (Spearman correlation coefficient: 0.30, 95% credible interval (0.12, 0.46)). These findings provide evidence that, like vaccination, immunity shortens duration acute principally by reducing Additionally, there appears be an inherent element immune response, or some other host factor, shapes ability clear persists sequential infections.

Language: Английский

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SARS-CoV-2 vaccination enhances the effector qualities of spike-specific T cells induced by COVID-19

Science Immunology, Journal Year: 2023, Volume and Issue: 8(90)

Published: Dec. 8, 2023

T cells are critical for immune protection against severe COVID-19, but it has remained unclear whether repeated exposure to SARS-CoV-2 antigens delivered in the context of vaccination fuels cell exhaustion or reshapes functionality. Here, we sampled convalescent donors with a history mild COVID-19 before and after profile functional spectrum hybrid immunity. Using combined single-cell technologies high-dimensional flow cytometry, found that frequencies capabilities spike-specific CD4

Language: Английский

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A mathematical model for the within-host (re)infection dynamics of SARS-CoV-2

Mathematical Biosciences, Journal Year: 2024, Volume and Issue: 371, P. 109178 - 109178

Published: March 13, 2024

Interactions between SARS-CoV-2 and the immune system during infection are complex. However, understanding within-host dynamics is of enormous importance for clinical public health outcomes. Current mathematical models focus on describing acute phase. Thereby they ignore important long-term post-acute effects. We present a model, which not only describes phase, but extends current approaches by also recapitulating clinically observed effects, such as recovery number susceptible epithelial cells to an initial pre-infection homeostatic level, permanent full clearance within individual, waning, formation capacity levels after infection. Finally, we used our model its description explore reinfection scenarios differentiating distinct variant-specific properties reinfecting virus. Together, model's ability describe provides more realistic key outcomes allows application in scenarios.

Language: Английский

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