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Top 10: August 27

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By Christian Hoffmann &
Bernd S. Kamps

27 August

Epidemiology

Maxmen A. Why the United States is having a coronavirus data crisis. Nature 2020, published 25 August. Full-text: https://www.nature.com/articles/d41586-020-02478-z

Is the United States emerging as a Second-World country from the SARS-CoV-2 pandemic? The country suffers from a dearth of data, writes Amy Maxmen in this Nature news article. Reliable information on who is infected, why and where is simply missing. How could this happen?

 

Models

Totura A, Livingston V, Frick O, Dyer D, Nichols D, Nalca A. Small Particle Aerosol Exposure of African Green Monkeys to MERS-CoV as a Model for Highly Pathogenic Coronavirus Infection. Emerg Infect Dis. 2020 Aug 3;26(12). PubMed: https://pubmed.gov/32744989. Full-text: https://doi.org/10.3201/eid2612.201664

Aysegul Nalca, Allison Totura and colleagues propose the development of an African green monkey (AGM) model of coronavirus infection by aerosol as a first step to establishing a platform for medical countermeasure testing against highly pathogenic coronaviruses. The authors observed a dose-dependent increase of respiratory disease signs after exposure to 103, 104, or 105 PFU target doses of aerosolized MERS-CoV. All 12 monkeys survived for the 28-day duration of the study.

 

Transmission

Simha PP, Rao PSM. Universal trends in human cough airflows at large distances featured. Physics of Fluids 32, 081905 (2020). Published 25 August. Full-text: https://doi.org/10.1063/5.0021666

Fine droplets can pass through layers of masks and are carried away by the exhaled airflow unlike larger droplets that settle down due to gravity. Now Padmanabha Prasanna Simha and Prasanna Simha Mohan Rao visualize the flow fields of coughs under various mouth covering scenarios. The results:

  1. N95 masks are the most effective at reducing the horizontal spread of a cough (spread: 0.1 and 0.25 meters).
  2. A simple disposable mask can reduce the spread to 0.5 meters, while an uncovered cough can travel up to 3 meters.
  3. Coughing into the elbow? Not very effective! Unless covered by a sleeve, a bare arm cannot form the proper seal against the nose necessary to obstruct airflow and a cough is able to leak through any openings and propagate in many directions.

Figure 6. Images illustrating various methods of covering the nose and mouth in order to provide context to Figs. 2 and 5. (a) No mask. (b) Surgical mask. (c) N95 mask. (d) Single hand. (e) Cupped hands. (f) Folded handkerchief. (g) Surgical mask along with a single hand covering the nose and mouth. (h) Elbow left bare covering the mouth. (i) Covering the nose and mouth while wearing a full sleeved shirt. Reproduced with permission.

 

Garigliany M, Van Laere AS, Clercx C, et al. SARS-CoV-2 Natural Transmission from Human to Cat, Belgium, March 2020. Emerg Infect Dis. 2020 Aug 12;26(12). PubMed: https://pubmed.gov/32788033. Full-text: https://doi.org/10.3201/eid2612.202223

And another human-to-cat transmission of SARS-CoV-2. The cat when still showing healthy behavior. Reproduced with permission.

 

Prevention

Blaisdell LL, Cohn W, Pavell JR, Rubin DS, Vergales JE. Preventing and Mitigating SARS-CoV-2 Transmission — Four Overnight Camps, Maine, June–August 2020. MMWR Morb Mortal Wkly Rep. ePub: 26 August 2020. DOI: http://dx.doi.org/10.15585/mmwr.mm6935e1

You can let the virus lose, but you can also control it. Here Laura Blaisdell et al. report insights from four overnight summer camps with 1,022 attendees where a multilayered prevention and mitigation strategy was successful in identifying and isolating three asymptomatic COVID-19 cases and preventing secondary transmission. Discover the meticulous planning and preparation of the camps. Perfection can be helpful in life.

 

Immunology

Fagiani F, Catanzaro M, Lanni C. Molecular features of IGHV3-53-encoded antibodies elicited by SARS-CoV-2. Sig Transduct Target Ther 5, 170 (2020). Full-text: https://doi.org/10.1038/s41392-020-00287-4

Francesca Fagiani, Michele Catanzaro and Cristina Lanni discuss in detail the paper by Yuan et al. we presented on July 14. Remember: Yuan and collaborators analyzed 294 anti-SARS-CoV-2 antibodies from COVID-19 patients and showed that the immunoglobulin heavy variable 3-53 (IGHV3-53) represents the most frequently used IGHV gene. They conclude that the characterization of these IGHV3-53 antibodies is a promising starting point for rational vaccine design.

Faginani et al. Figure 1. Representation of “reverse vaccinology 2.0” theory: focus on the molecular features of IGHV3-53-encoded antibodies. Monoclonal antibodies are obtained from seropositive subjects, isolated and structurally characterized. Based on the molecular features, a structure-based immunogen is designed and then tested in appropriate animal models. Reproduced with permission.

 

Vaccine

Slaoui M, Hepburn M. Developing Safe and Effective Covid Vaccines — Operation Warp Speed’s Strategy and Approach. N Engl J Med 2020, published 26 August. Full-text: https://doi.org/10.1056/NEJMp2027405

What is OWS and what does it do? Moncef Slaoui and Matthew Hepburn from Operation Warp Speed explain the forces behind a national vaccine strategy. The players: Pfizer and BioNTech, AstraZeneca and Oxford University, Janssen, Moderna, Janssen, Novavax, Sanofi/GSK. Will they succeed in this unprecedented endeavor?

 

Diagnostics

Perera RAPM, Tso E, Tsang OTY, et al. SARS-CoV-2 Virus Culture and Subgenomic RNA for Respiratory Specimens from Patients with Mild Coronavirus Disease. Emerg Infect Dis. 2020 Aug 4;26(11). PubMed: https://pubmed.gov/32749957. Full-text: https://doi.org/10.3201/eid2611.203219

Viral RNA detection by RT-PCR does not prove the presence of infectious virus; culture isolation of virus is a better indication of contagiousness. Now Malik Peiris, Ranawaka Perera and colleagues attempt viral isolation in 68 specimens from 35 patients at different times after symptom onset to define the kinetics of viral isolation in upper respiratory specimens. Their findings suggest that patients with mild or moderate illness might be less contagious 8 days after symptom onset. Mildly ill patients who have clinically recovered and are not immunocompromised might therefore be discharged from containment > 9 days after symptom onset, as long as they are not being discharged into settings that contain other highly vulnerable persons.

 

Collateral Effects

Hamadani JD, Hasan MI, Baldi AJ, et al. Immediate impact of stay-at-home orders to control COVID-19 transmission on socioeconomic conditions, food insecurity, mental health, and intimate partner violence in Bangladeshi women and their families: an interrupted time series. Lancet Global Health 2020, published 25 August. Full-text:: https://doi.org/10.1016/S2214-109X(20)30366-1

In many countries, lockdowns exacerbate the risk of food insecurity and intimate partner violence. Here Sant-Rayn Pasricha, Jena Derakhshani Hamadani and colleagues analyze the impact lockdown orders on women and their families in rural Bangladesh. They randomly selected and invited the mothers of 3016 children to participate in the study, 2424 of whom provided consent. Almost all women reported a reduction in paid work for the family. Median monthly family income fell from US$212 at baseline to $59 during lockdown, and the proportion of families earning less than $1·90 per day rose from almost 0% to 47%. Before the pandemic, 5.6% and 2.7% experienced moderate and severe food insecurity, respectively. This increased to 36.5% and 15.3% during the lockdown. Find more information about intimate violence (emotional, physical, sexual).

 

Beyond your plate borders

McGuire AL, Gabriel S, Tishkoff SA, et al. The road ahead in genetics and genomics. Nat Rev Genet. 2020 Aug 24:1-16. PubMed: https://pubmed.gov/32839576. Full-text: https://doi.org/10.1038/s41576-020-0272-6

Twelve leading researchers reflect on the key challenges and opportunities faced by the field of genetics and genomics. Read about ethical and policy issues, privacy and discrimination, humility and solidarity, and why the genomics of the future must be a genomics for all, regardless of ethnicity, geography or ability to pay. Thirteen fascinating pages for the upcoming weekend.