Copy-editor: Rob Camp
Virology
Wang K, Chen W, Zhang Z, et al. CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells. Sig Transduct Target Ther 5, 283 (2020). Full-text: https://doi.org/10.1038/s41392-020-00426-x
Might there be a hitherto clandestine loophole for SARS-CoV-2 to enter into human cells? Here, Zhi-Nan Chen, Ke Wang and co-authors wonder that although angiotensin-converting enzyme 2 (ACE2) – the receptor which mediates the infection of cells by binding to the spike protein – is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. They describe an interaction between the host cell receptor CD147 and the SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody meplazumab inhibited SARS-CoV-2 amplification. The authors suggest that a novel viral entry route via the CD147-spike protein might provide a new target for developing drugs against SARS-CoV-2.
Transmission
Alsved M, Matamis A, Bohlin R, et al. Exhaled respiratory particles during singing and talking. Aerosol Research Letters 2020, published 17 September. Full-text: https://doi.org/10.1080/02786826.2020.1812502
Aerosols are emitted from breathing, talking, coughing and sneezing. Over time, normal breathing can generate more viable viral aerosol than even coughing! In this study, Jacob Löhndal, Malin Alsved and colleagues investigated aerosol and droplet emissions during singing, as compared to talking and breathing. As expected, normal singing generated significantly more aerosol particles than normal talking and loud singing produced more particles than normal singing. (Advice of the Editors: Get vaccinated – and then wait 57 days – before you go back to your weekly choir sessions.)
Immunology
McMahan K, Yu J, Mercado NB, et al. Correlates of protection against SARS-CoV-2 in rhesus macaques. Nature 2020, published 4 December. Full-text: https://doi.org/10.1038/s41586-020-03041-6
Dan Barouch, Katherine McMahan and colleagues from Harvard show that adoptive transfer of purified IgG from convalescent macaques protects naïve recipient rhesus macaques against SARS-CoV-2 challenge in a dose dependent fashion; relatively low antibody titers were sufficient for protection against SARS-CoV-2 in rhesus macaques whereas higher antibody titers were required for therapy of SARS-CoV-2 infection in macaques. Depletion of CD8+ T cells in convalescent animals partially depletes the protective efficacy of natural immunity against SARS-CoV-2 re-challenge.
Starr TN, Greaney AJ, Addetia A, et al. Prospective mapping of viral mutations that escape antibodies used to treat COVID-19. bioRxiv 2020, posted 1 December. Full-text: https://doi.org/10.1101/2020.11.30.405472
Jesse Bloom, Tyler Starr and colleagues from the Fred Hutchinson Cancer Research Center in Seattle, US, mapped SARS-CoV-2 mutation that could prevent binding by the three monoclonal antibodies LY-CoV016 (Eli Lilly; which is different from bamlanivimab [LY-CoV555]) and casirivimab and imdevimab (REGN-COV2). They identified a single amino-acid mutation that fully escapes the REGN-COV2 cocktail. Please note: these findings have not yet been peer reviewed.
Pathogenesis
Simoneau CR, Ott M. Modeling Multi-organ Infection by SARS-CoV-2 Using Stem Cell Technology. Cell Stem Cell 2020, published 3 December. Full-text: https://doi.org/10.1016/j.stem.2020.11.012
COVID-19 is a multi-organ disease causing characteristic complications. In this mini-review, Camille Simoneau and Melanie Ott from the Gladstone Institute of Virology, San Francisco, show that stem cell models of various organ systems—most prominently, lung, gut, heart, and brain—are at the forefront of studies aimed at understanding the role of direct infection in COVID-19 multi-organ dysfunction. A perfect reading for the weekend!
Diagnostics
Wang D, He S, Wang X, et al. Rapid lateral flow immunoassay for the fluorescence detection of SARS-CoV-2 RNA. Nat Biomed Eng 2020, published 3 December. Full-text: https://doi.org/10.1038/s41551-020-00655-z
The authors describe an inexpensive amplification-free nucleic acid immunoassay for the fluorescence detection of SARS-CoV-2 RNA in less than an hour. In a multi-hospital randomized double-blind trial involving 734 samples (593 throat swabs and 141 sputum), the assay achieved sensitivities of 100% and specificities of 99% for both types of sample.
Larremore DB, Toomre D, Parker R. Modeling the effectiveness of olfactory testing to limit SARS-2-CoV transmission. medRxiv 2020, posted 2 December. Full-text: https://doi.org/10.1101/2020.11.30.20241174
Olfactory dysfunction – hyposmia or anosmia – occurs in up to 80% of SARS-CoV-2 infected individuals if standardized olfactory dysfunction test is performed, even in those who remain otherwise asymptomatic. Here, the authors from the University of Colorado Boulder suggest that mass-produced, low-cost and self-administered olfactory tests might reduce the spread of SARS-CoV-2. Interesting approach but attention: this is just a model.
Severe COVID
Kaeuffer C, Le Hyaric C, Fabacher T, et al. Clinical characteristics and risk factors associated with severe COVID-19: prospective analysis of 1,045 hospitalised cases in North-Eastern France, March 2020. Eurosurveill 2020, published 3 December. Full-text: https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.48.2000895
This non-interventional prospective study (1045 adult COVID-19 patients hospitalized in two different hospitals in Alsace, France: Strasbourg University Hospital and Mulhouse Hospital in March 2020) presents a wealth of data. Advanced age, being male, inflammation parameters and dyspnea were associated with the development of severe disease and death. Being overweight or obese was associated with severe disease only, whereas co-morbidities such as chronic kidney disease, diabetes and immunosuppression increased the risk of death.
Beyond Corona
Mitchell MJ, Billingsley MM, Haley RM, et al. , M.J., Billingsley, M.M., Haley, R.M. et al. Engineering precision nanoparticles for drug delivery. Nat Rev Drug Discov (2020). Full-text: https://doi.org/10.1038/s41573-020-0090-8
In recent years, nanoparticles have been developed to navigate biological barriers — systemic, microenvironmental and cellular — that are heterogeneous across patient populations and diseases. In this 294-citation review, Robert Langer, Michael Mitchell and colleagues discuss advances in nanoparticle design. Optimized drug delivery in a personalized manner might ultimately have an impact on patient outcome.
Press
Zimmer K, Weiland N. Many Trial Volunteers Got Placebo Vaccines. Do They Now Deserve the Real Ones? The New York Times 2020, published 2 December. Full-text: https://www.nytimes.com/2020/12/02/health/covid-vaccine-placebo-group.html
Some vaccine experts worry that “unblinding” the trials and giving all of the volunteers vaccines would tarnish the long-term results. See also Placebo-Controlled Trials of Covid-19 Vaccines — Why We Still Need Them. N Engl J Med 2020, published 2 December. Full-text: https://doi.org/10.1056/NEJMp2033538
Spanish
If you read Spanish, read Grasso D, Llaneras K, Zafra M. Aislar rápido y cortar contagios: cómo los test de antígenos están cambiando la pandemia. El País 2020, published 5 December. Full-text: https://elpais.com/sociedad/2020-12-05/aislar-rapido-y-cortar-contagios-como-los-test-de-antigenos-estan-cambiando-la-pandemia.html
Estas pruebas se están convirtiendo en un arma clave en la segunda ola y ya se usan como análisis de referencia en hospitales y primaria. Son lo bastante sensibles para detectar personas contagiosas.
French
Remember the paper COVID-19 Outbreak Associated with a 10-Day Motorcycle Rally in a Neighboring State — Minnesota, August–September 2020 that we presented on 21 November? If you read French, read Le Bars S. Une troisième vague de Covid-19 au milieu de nulle part : le Dakota du Sud, terrain fertile pour l’épidémie. Le Monde 2020, published 5 December. Full-text : https://www.lemonde.fr/m-le-mag/article/2020/12/05/le-dakota-du-sud-un-terrain-fertile-pour-le-covid-19_6062267_4500055.html
Cet Etat américain, rural et conservateur, dont les habitants « n’aiment pas qu’on se mêle de leurs affaires », est majoritairement réfractaire à toute mesure sanitaire. Au nom de la liberté. (Ndlr : Nous devrions peut-être leur expliquer le vrai sens de la parole liberté.)
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By Christian Hoffmann &
Bernd Sebastian Kamps
Copy-editor: Rob Camp