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1.
Viruses ; 14(9)2022 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-36146877

RESUMEN

The Delta variant of SARS-CoV-2 has caused many breakthrough infections in fully vaccinated individuals. While vaccine status did not generally impact the number of viral RNA genome copies in nasopharyngeal swabs of breakthrough patients, as measured by Ct values, it has been previously found to decrease the infectious viral load in symptomatic patients. We quantified the viral RNA, infectious virus, and anti-spike IgA in nasopharyngeal swabs collected from individuals asymptomatically infected with the Delta variant of SARS-CoV-2. Vaccination decreased the infectious viral load, but not the amount of viral RNA. Furthermore, vaccinees with asymptomatic infections had significantly higher levels of anti-spike IgA in their nasal secretions compared to unvaccinated individuals with asymptomatic infections. Thus, vaccination may decrease the transmission risk of Delta, and perhaps other variants, despite not affecting the amount of viral RNA measured in nasopharyngeal swabs.


Asunto(s)
COVID-19 , Vacunas , Infecciones Asintomáticas , COVID-19/prevención & control , Humanos , Inmunoglobulina A , ARN Viral/genética , SARS-CoV-2/genética , Vacunación , Carga Viral
2.
J Pediatric Infect Dis Soc ; 11(12): 550-556, 2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36043454

RESUMEN

Children are capable of initiating COVID-19 transmission into households, but many questions remain about the impact of vaccination on transmission. Data from a COVID-19 Delta variant outbreak at an overnight camp in Texas during June 23-27, 2021, were analyzed. The camp had 451 attendees, including 364 youths aged  < 18 years and 87 adults. Detailed interviews were conducted with 92 (20.4%) of consenting attendees and 117 household members of interviewed attendees with COVID-19. Among 450 attendees with known case status, the attack rate was 41%, including 42% among youths; attack rates were lower among vaccinated (13%) than among unvaccinated youths (48%). The secondary attack rate was 51% among 115 household contacts of 55 interviewed index patients. Secondary infections occurred in 67% of unvaccinated household members and 33% of fully or partially vaccinated household members. Analyses suggested that household member vaccination and camp attendee masking at home protected against household transmission.


Asunto(s)
COVID-19 , SARS-CoV-2 , Adulto , Niño , Humanos , Adolescente , Anciano , Incidencia , Texas/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Brotes de Enfermedades , Vacunación
3.
J Mol Diagn ; 24(5): 455-461, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35218945

RESUMEN

Tracking new and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has become increasingly important for public health responses, primarily because of variant-dependent transmission, disease severity, and treatment decisions. This evaluation compared Seegene Technologies Novaplex SARS-CoV-2 Variants I, II, and IV (I,II&IV) assays to detect known SARS-CoV-2 variants using traditional spike gene Sanger sequencing results as the gold standard reference. Both RNA extraction and extraction-free protocols were assessed. A total of 156 samples were included in this study. There was 100% (109/109) overall agreement (95% CI, 96.7%-100%) between the spike gene sequencing and the I,II&IV results using extracted RNA for the variants included in the Novaplex assay menus. The RNA extraction-free method was 91.7% (143/156) as sensitive (95% CI, 86.2%-95.5%) as the traditional RNA extraction method. Using the extraction-free method on samples with higher cycle threshold values (>30) resulted in some mutations not being detected, presumably due to lower nucleic acid concentrations in the original samples. In conclusion, the I,II&IV assays provide an accurate, rapid, and less labor-intensive method for detecting SARS-CoV-2 and identifying known variants of interest and concern. The RNA extraction-free method for samples with cycle threshold of <30 could be cost-effective for surveillance purposes. However, spike gene sequencing retains the advantage of detecting more and new variants.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Humanos , Mutación , ARN , SARS-CoV-2/genética
4.
Elife ; 102021 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-34581669

RESUMEN

High-throughput genomics of SARS-CoV-2 is essential to characterize virus evolution and to identify adaptations that affect pathogenicity or transmission. While single-nucleotide variations (SNVs) are commonly considered as driving virus adaption, RNA recombination events that delete or insert nucleic acid sequences are also critical. Whole genome targeting sequencing of SARS-CoV-2 is typically achieved using pairs of primers to generate cDNA amplicons suitable for next-generation sequencing (NGS). However, paired-primer approaches impose constraints on where primers can be designed, how many amplicons are synthesized and requires multiple PCR reactions with non-overlapping primer pools. This imparts sensitivity to underlying SNVs and fails to resolve RNA recombination junctions that are not flanked by primer pairs. To address these limitations, we have designed an approach called 'Tiled-ClickSeq', which uses hundreds of tiled-primers spaced evenly along the virus genome in a single reverse-transcription reaction. The other end of the cDNA amplicon is generated by azido-nucleotides that stochastically terminate cDNA synthesis, removing the need for a paired-primer. A sequencing adaptor containing a Unique Molecular Identifier (UMI) is appended to the cDNA fragment using click-chemistry and a PCR reaction generates a final NGS library. Tiled-ClickSeq provides complete genome coverage, including the 5'UTR, at high depth and specificity to the virus on both Illumina and Nanopore NGS platforms. Here, we analyze multiple SARS-CoV-2 isolates and clinical samples to simultaneously characterize minority variants, sub-genomic mRNAs (sgmRNAs), structural variants (SVs) and D-RNAs. Tiled-ClickSeq therefore provides a convenient and robust platform for SARS-CoV-2 genomics that captures the full range of RNA species in a single, simple assay.


Asunto(s)
Secuencia de Bases , Coronavirus/genética , Genoma Viral , ARN , SARS-CoV-2/genética , COVID-19/virología , ADN Complementario , Biblioteca de Genes , Genómica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Nanoporos , Reacción en Cadena de la Polimerasa , ARN Mensajero , ARN Viral/genética , Recombinación Genética , Secuenciación Completa del Genoma
5.
Policy Sci ; 54(3): 691-706, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34075260

RESUMEN

This article seeks to critique and extend recent work in the policy sciences, by Maor in particular, on disproportionate policy making-including policy overreaction and underreaction. While the disproportionate policy making thesis does help address assumptions that something is amiss in the policy process by capturing an imbalance between policy problems and the interventions to address them, we argue that it does not pay sufficient attention to politics. We present a heuristic which includes political perception of both programme and political threats. Our core argument is that much of what is considered disproportionate policy making, can in fact also be considered proportionate politics. Our analysis paves the way for a more holistic and political understanding of policy dynamics.

6.
bioRxiv ; 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33758846

RESUMEN

High-throughput genomics of SARS-CoV-2 is essential to characterize virus evolution and to identify adaptations that affect pathogenicity or transmission. While single-nucleotide variations (SNVs) are commonly considered as driving virus adaption, RNA recombination events that delete or insert nucleic acid sequences are also critical. Whole genome targeting sequencing of SARS-CoV-2 is typically achieved using pairs of primers to generate cDNA amplicons suitable for Next-Generation Sequencing (NGS). However, paired-primer approaches impose constraints on where primers can be designed, how many amplicons are synthesized and requires multiple PCR reactions with non-overlapping primer pools. This imparts sensitivity to underlying SNVs and fails to resolve RNA recombination junctions that are not flanked by primer pairs. To address these limitations, we have designed an approach called 'Tiled-ClickSeq', which uses hundreds of tiled-primers spaced evenly along the virus genome in a single reverse-transcription reaction. The other end of the cDNA amplicon is generated by azido-nucleotides that stochastically terminate cDNA synthesis, removing the need for a paired-primer. A sequencing adaptor containing a Unique Molecular Identifier (UMI) is appended to the cDNA fragment using click-chemistry and a PCR reaction generates a final NGS library. Tiled-ClickSeq provides complete genome coverage, including the 5'UTR, at high depth and specificity to the virus on both Illumina and Nanopore NGS platforms. Here, we analyze multiple SARS-CoV-2 isolates and clinical samples to simultaneously characterize minority variants, sub-genomic mRNAs (sgmRNAs), structural variants (SVs) and D-RNAs. Tiled-ClickSeq therefore provides a convenient and robust platform for SARS-CoV-2 genomics that captures the full range of RNA species in a single, simple assay.

7.
Policy Sci ; 53(2): 225-241, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32313308

RESUMEN

The world is in the grip of a crisis that stands unprecedented in living memory. The COVID-19 pandemic is urgent, global in scale, and massive in impacts. Following Harold D. Lasswell's goal for the policy sciences to offer insights into unfolding phenomena, this commentary draws on the lessons of the policy sciences literature to understand the dynamics related to COVID-19. We explore the ways in which scientific and technical expertise, emotions, and narratives influence policy decisions and shape relationships among citizens, organizations, and governments. We discuss varied processes of adaptation and change, including learning, surges in policy responses, alterations in networks (locally and globally), implementing policies across transboundary issues, and assessing policy success and failure. We conclude by identifying understudied aspects of the policy sciences that deserve attention in the pandemic's aftermath.

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