Viral dynamics of SARS-CoV-2 variants in vaccinated and unvaccinated individuals
| Autor: | Christina D. Mack, Anne E. Watkins, Mallery I. Breban, Yonatan H. Grad, Matthew MacKay, Stephen M Kissler, Nathan D. Grubaugh, Radhika M. Samant, Tim Baker, David D. Ho, Jessica Metti, Christopher E. Mason, Caroline G. Tai, Gaurav Khullar, Joseph R. Fauver, Rachel Baits, Deverick J. Anderson, Daisy Salgado, Joel T. Dudley |
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| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Transmission (medicine) business.industry Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Alpha (ethology) Virology Anterior nares Clearance time Vaccination 03 medical and health sciences 030104 developmental biology 0302 clinical medicine medicine.anatomical_structure Viral dynamics medicine 030212 general & internal medicine business Clearance |
| Popis: | BackgroundThe alpha and delta SARS-CoV-2 variants have been responsible for major recent waves of COVID-19 despite increasing vaccination rates. The reasons for the increased transmissibility of these variants and for the reduced transmissibility of vaccine breakthrough infections are unclear.MethodsWe quantified the course of viral proliferation and clearance for 173 individuals with acute SARS-CoV-2 infections using longitudinal quantitative RT-PCR tests conducted using anterior nares/oropharyngeal samples (n = 199,941) as part of the National Basketball Association’s (NBA) occupational health program between November 28th, 2020, and August 11th, 2021. We measured the duration of viral proliferation and clearance and the peak viral concentration separately for individuals infected with alpha, delta, and non-variants of interest/variants of concern (non-VOI/VOC), and for vaccinated and unvaccinated individuals.ResultsThe mean viral trajectories of alpha and delta infections resembled those of non-VOI/VOC infections. Vaccine breakthrough infections exhibited similar proliferation dynamics as infections in unvaccinated individuals (mean peak Ct: 20.5, 95% credible interval [19.0, 21.0] vs. 20.7 [19.8, 20.2], and mean proliferation time 3.2 days [2.5, 4.0] vs. 3.5 days [3.0, 4.0]); however, vaccinated individuals exhibited faster clearance (mean clearance time: 5.5 days [4.6, 6.6] vs. 7.5 days [6.8, 8.2]).ConclusionsAlpha, delta, and non-VOI/VOC infections feature similar viral trajectories. Acute infections in vaccinated and unvaccinated people feature similar proliferation and peak Ct, but vaccinated individuals cleared the infection more quickly. Viral concentrations do not fully explain the differences in infectiousness between SARS-CoV-2 variants, and mitigation measures are needed to limit transmission from vaccinated individuals. |
| Databáze: | OpenAIRE |
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