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28 October
Virology
V’kovski P, Kratzel A, Steiner S, et al. Coronavirus biology and replication: implications for SARS-CoV-2. Nat Rev Microbiol 2020, published 28 October. Full-text: https://doi.org/10.1038/s41579-020-00468-6
In contrast to the SARS- CoV epidemic of almost 20 years ago, improved technologies, such as transcriptomics, proteomics, single-cell RNA sequencing, global single-cell profiling of patient samples, advanced primary 3D cell cultures and rapid reverse genetics, have been valuable tools to understand and tackle SARS- CoV-2 infections. Follow the authors on a 13-page review of the first discoveries that shape our current understanding of SARS- CoV-2 infection throughout the intracellular viral life cycle and relate that to our knowledge of coronavirus biology.
Transmission
Lee EC, Wada NI, Grabowski MK, Gurley ES, Lessler J. The engines of SARS-CoV-2 spread. Science. 2020 Oct 23;370(6515):406-407. PubMed: https://pubmed.gov/33093098. Full-text: https://doi.org/10.1126/science.abd8755
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is mostly transmitted within households and household-like settings. A decreasing proportion of transmission events take place at increasing spatial scales, but these events become more critical for sustaining the pandemic. Discover the fundamental engines that drive the SARS-CoV-2 pandemic in this Science Perspective.
Teran RA, Ghinai I, Gretsch S, et al. COVID-19 Outbreak Among a University’s Men’s and Women’s Soccer Teams — Chicago, Illinois, July–August 2020. MMWR Morb Mortal Wkly Rep. ePub: 27 October 2020. Full-text: http://dx.doi.org/10.15585/mmwr.mm6943e5
Investigation of 17 COVID-19 cases among a university’s men’s and women’s soccer team identified numerous social gatherings as possible transmission events. Minimal mask use and social distancing resulted in rapid spread among students who live, practice, and socialize together. Nothing truly new – we should stop reporting on SARS-CoV-2 transmission during social gatherings.
Immunology
Fox A, Marino J, Amanat F, et al. Robust and specific secretory IgA against SARS-CoV-2 detected in human milk. iScience 2020, published 27 October. Full-text: https://doi.org/10.1016/j.isci.2020.101735
Rebecca Powell, Alisa Fox and colleagues report significant specific IgA reactivity to the full Spike, while 80% exhibited significant IgA and secretory (s)Ab binding to the receptor binding domain (RBD) in human milk samples from 8 COVID-19-recovered and 7 COVID-19-suspected donors. These data might indicate that a robust sIgA-dominant SARS-CoV-2 Ab response in human milk after infection should be expected in a significant majority of individuals. The authors also recommend further research to determine the potential for exploiting extracted milk sIgA for therapeutic use. How practical will that be?
Vaccine
Hodgson SH, Mansatta K, Mallett G, Harris V, Emary KWR, Pollard AJ. What defines an efficacious COVID-19 vaccine? A review of the challenges assessing the clinical efficacy of vaccines against SARS-CoV-2. Lancet Infect Dis 2020, published 27 October. Full-text: https://doi.org/10.1016/S1473-3099(20)30773-8
A vaccine against SARS-CoV-2 might act against infection, disease, or transmission and a vaccine capable of reducing any of these elements could contribute to disease control. However, the most important efficacy endpoint, protection against severe disease and death, is difficult to assess in phase 3 clinical trials. In this review, Susanne Hodgson and colleagues explore the challenges in assessing the efficacy of candidate SARS-CoV-2 vaccines, discuss the caveats needed to interpret reported efficacy endpoints, and provide insight into answering the seemingly simple question, “Does this COVID-19 vaccine work?” Remember: the fundamental understanding of the pathogen is still evolving.
Clinical
Brandén M, Aradhya S, Kolk M, et al. Residential context and COVID-19 mortality among adults aged 70 years and older in Stockholm: a population-based, observational study using individual-level data. Lancet Healthy Longevity 2020, published 27 October. Full-text: https://doi.org/10.1016/S2666-7568(20)30016-7
Living in a care home is associated with increased mortality – we knew that. Living in neighbourhoods with high population density (≥5000 individuals per km2) is associated with higher COVID-19 mortality (1·7; 1·1–2·4) compared with living in least densely populated neighbourhoods (0 to <150 individuals per km2) – we knew that, too. Living with someone of working age (<66 years), when compared with living in a household with individuals aged 66 years or older, was associated with increased COVID-19 mortality (hazard ratio 1·6; 95% CI 1·3–2·0). We imagined that. It was reported by Maria Brandén and colleagues after analyzing 274,712 individuals aged 70 years or older and residing in Stockholm. See also the comment by Roxby AC, Gure TR: Lessons from Sweden: where can older adults shelter from COVID-19? Lancet Healthy Longevity 2020, published 27 October. Full-text: https://doi.org/10.1016/S2666-7568(20)30035-0
Comorbidities
Altuntas F, Ata N, Yigenoglu TN, et al. COVID-19 in hematopoietic cell transplant recipients. Bone Marrow Transplant (2020). https://doi.org/10.1038/s41409-020-01084-x
Case fatality rate (CFR) was 5.6% in patients without cancer, 11.8 in patients with hematological malignancy and 15.6% in hematopoietic cell transplant (HCT) recipients. The CFR in HCT recipients who were not receiving immunosuppressive agents at the time of COVID-19 diagnosis was 11.5%, whereas it was 33% in HCT recipients who were receiving an immunosuppressive agent at the time of COVID-19 diagnosis. This is the result of a study by Fefzi Altuntas and colleagues who analyzed the outcome of 21 HCT recipients, 465 comorbid disease-matched hospitalized COVID-19 patients with hematological malignancy but without HCT, and 497 comorbid disease-matched hospitalized COVID-19 patients without cancer (n = 497).
Yang H, Chen W, Hu Y, et al. Pre-pandemic psychiatric disorders and risk of COVID-19: a UK Biobank cohort analysis. Lancet Healthy Longevity 2020, published 26 October. Full-text: https://doi.org/10.1016/S2666-7568(20)30013-1
Psychiatric morbidities have been associated with a risk of severe infections through compromised immunity, health behaviors, or both. After analyzing 421 014 Biobank participants in the UK (mean age 68 years), Huan Song, Huazhen Yang and colleagues from West China Biomedical Big Data Center, Sichuan University, observed an elevated risk of COVID-19 among UK individuals with pre-pandemic psychiatric disorders compared with that of individuals without such conditions. The fully adjusted ORs were 1·44 (95% CI 1·28–1·62) for All COVID-19 cases, 1·55 (1·34–1·78) for Inpatient COVID-19 cases, and 2·03 (1·59–2·59) for COVID-19-related deaths.