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Paper of the Day
Marks M, Millat-Martinez P, Ouchi D, et al. Transmission of COVID-19 in 282 clusters in Catalonia, Spain: a cohort study. Lancet Infect Dis 2021, published 2 February. Full-text: https://doi.org/10.1016/S1473-3099(20)30985-3
A ground-breaking study! Oriol Mitjà, Michael Marks and colleagues found that increasing viral load values in nasopharyngeal swabs of patients with COVID-19 were associated with a greater risk of transmission, measured by SARS-CoV-2 PCR positivity among contacts, and with a higher risk of transmission in a household environment compared with other indoor situations. Read also the comment by Cornelissen L. Understanding the drivers of transmission of SARS-CoV-2. Lancet Infect Dis 2021, published 2 February. Full-text: https://doi.org/10.1016/S1473-3099(21)00005-0
Kissane E, Madrigal A. It’s Time: The COVID Tracking Project Will Soon Come to an End. The COVID Tracking Project 2021, published 1 February. Full-text: https://covidtracking.com/analysis-updates/covid-tracking-project-end-march-7
After a year of collecting, analyzing, and interpreting COVID-19 data for the United States, we’re ending our data compilation work in early March. When should COVID Reference shut down its activity?
Krammer F. Pandemic Vaccines: How Are We Going to Be Better Prepared Next Time? Med (N Y). 2020 Dec 18;1(1):28-32. PubMed: https://pubmed.gov/33521752. Full-text: https://doi.org/10.1016/j.medj.2020.11.004
We did good, but in the future, we can do better. Discover Florian Krammer’s 3-month timeline for developing vaccines against the next pandemic.
Figure 1. Overview of the current situation with sars-cov-2 and an ideal scenario from the vaccinology point of view. (A) Current, suboptimal situation and (B) ideal scenario.
Sokal A, Chappert P, Barba-Spaeth G, et al. Maturation and persistence of the anti-SARS-CoV-2 memory B cell response. Cell 2021, published 2 February. Full-text: https://doi.org/10.1016/j.cell.2021.01.050
Excellent news from France: Matthieu Mahévas, Aurélien Sokal and colleagues longitudinally profiled memory B cells and found remarkable stability of the overall spike-specific memory B cell population up to 6 months after infection. Antigen-driven activation persisted and matured up to 6 months after SARS-CoV-2 infection and may provide long-term protection.
Bolouri H, Speake C, Skibinski D, et al. The COVID-19 immune landscape is dynamically and reversibly correlated with disease severity. J Clin Invest 2021, published 1 February. Full-text: https://www.jci.org/articles/view/143648
After assessing the immune landscape in longitudinal whole-blood specimens from 59 patients presenting with acute COVID-19, the authors found that the immune landscape in COVID-19 formed 3 dominant clusters, which correlate with disease severity. They identified coordinated immune alterations accompanying clinical improvement or decline that were also seen in patients who experienced an IL-6 pathway blockade.
Petter Brodin discusses the current understanding of the immunological determinants of COVID-19 disease presentation and severity and relate this to known immune system differences between young people and old and between men and women, as well as other factors associated with different disease presentations and severity.
Figure 1. Coronavirus recognition and immune response. | a, SARS-CoV-2 viruses bind to the ACE2 receptor for cell entry. Viral RNA is recognized by TLR3, which triggers transcriptional responses and cytoplasmic changes that activate the NLRP3 inflammasome. This leads to cleavage of precursor IL-1β (pro-IL-1β), pro-IL-18 and gasdermin D, allowing secretion of IL-1β and IL-18. These changes collectively induce pyroptosis, inflammation and coagulopathy. b, Secreted IL-18 together with IL-12 from myeloid cells stimulate TH1 immunity and natural killer cells to secrete IFN-γ. c, A key feature of coronaviruses (MERS-CoV, SARS-CoV) is a capability to inhibit and delay the type I IFN response, leading to increased viral replication and severe immunopathology.
Dong J, Zost SJ, Greaney AJ, et al. Genetic and structural basis for recognition of SARS-CoV-2 spike protein by a two-antibody cocktail. bioRxiv 2021, posted 28 January. Full-text: https://doi.org/10.1101/2021.01.27.428529
James Crowe, Jesse Bloom, Jinhui Dong and colleagues determined the structures of two human monoclonal antibodies COV2-2196 and COV2-2130, which form the basis of the investigational antibody cocktail AZD7442, in complex with the receptor binding domain (RBD) of SARS-CoV-2.
Figure 2 e.
Saadat S, Rikhtegaran-Tehrani Z, Logue J, et al. Single Dose Vaccination in Healthcare Workers Previously Infected with SARS-CoV-2. medRxiv 2021, posted 1 February. Full-text: https://doi.org/10.1101/2021.01.30.21250843
The same direction: Healthcare workers (HCW) with prior COVID-19 showed clear secondary antibody responses to vaccination with IgG spike binding titers rapidly increasing by 7 days and peaking by days 10 and 14 post-vaccination. The authors’ conclusion: in times of vaccine shortage 1) a single dose of vaccine for patients already having had laboratory-confirmed COVID-19; and 2) patients who have had laboratory-confirmed COVID-19 can be placed lower on the vaccination priority list.
Figure 1. Anti-SARS-CoV-2 antibody responses after single dose of vaccination. After COVID-19 vaccination, plasma was drawn at 0, 7, 10, and 14 days and IgG binding titers against spike measured by ELISA and live virus neutralization at Day 0 and 14 measured. Single time point was also measured among COVID-19 outpatients or inpatients whose blood was drawn during peak antibody production (1-2 months after onset of symptoms). A) IgG spike trimer half-maximal titers. By 7 days and continuing to 14 days post vaccination HCW with prior COVID-19 who received a single… | Continue reading at https://doi.org/10.1101/2021.01.30.21250843 .
RECOVERY Collaborative Group. Azithromycin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial. Lancet 2021, published 2 February. Full-text: https://doi.org/10.1016/S0140-6736(21)00149-5
In patients admitted to hospital with COVID-19, azithromycin did not improve survival or other pre-specified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restricted to patients in whom there is a clear antimicrobial indication. Read also the comment by Berwanger O. Azithromycin, RECOVERY, and the power of large, simple trials. Lancet 2021, published 2 February. Full-text: https://doi.org/10.1016/S0140-6736(21)00307-X