Vaccine

Wang P, Lihong L, Iketani S, et al. Increased Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7 to Antibody Neutralization. bioRxiv 2021, posted 26 January. Full-text: https://doi.org/10.1101/2021.01.25.428137

E484K is the bad boy on the block. David Ho, Pengfai Wang and colleagues at Columbia University produced retroviruses with spike proteins incorporating each of B1351’s mutations separately, as well as all at once. E484K accounted for much of the effect. The serum of 12 people vaccinated with Moderna’s vaccine and 10 people vaccinated with the Pfizer-BioNTech vaccine was six to nine times less potent against B.1.351. Serum from 20 previously infected people was 11 to 33 times less potent.

 

Kupferschmidt 20210126. Vaccine 2.0: Moderna and other companies plan tweaks that would protect against new coronavirus mutations. Science 2021, published 26 January. Full-text: https://www.sciencemag.org/news/2021/01/vaccine-20-moderna-and-other-companies-plan-tweaks-would-protect-against-new

Antibodies triggered by the vaccine may be a little less potent against the new variant B.1.351, first described in South Africa, vs the one the vaccine was developed for. So, researchers were perhaps relieved to hear the company will start development of booster shots tailored to B.1.351 and other variants.

 

Brunning A. How are RNA vaccines made? Periodic Graphics 2021, published 3 January. Link: https://cen.acs.org/pharmaceuticals/vaccines/Periodic-Graphics-RNA-vaccines-made/99/i1

RNA vaccines produced by Pfizer-BioNTech and Moderna have become the first COVID-19 vaccines. How are these vaccines made?

 

Epidemiology

Sabino EC, Buss LF, Carvalho MPS, et al. Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence. Lancet 2021, published 27 January. Full-text: https://doi.org/10.1016/S0140-6736(21)00183-5

This is not a retraction of the pre-print paper posted on 21 September or of the 8 December Science article below. But in view of the dramatic second wave of the COVID-19 pandemic in Manaus (if you read Spanish, read 111, 222, 333, 444, 555, 666, 777), it is difficult to believe that there has ever been a “75% attack rate of SARS-CoV-2 in the Brazilian Amazon”. [Buss LF, Prete Jr A, Abrahim CMM, et al. Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic. Science 2020, published 8 December. Full-text: https://doi.org/10.1126/science.abe9728]. The future will tell.

 

Lopreite M, Panzarasa P, Puliga M, et al. Early warnings of COVID-19 outbreaks across Europe from social media. Sci Rep 11, 2147 (2021). https://doi.org/10.1038/s41598-021-81333-1

The authors analyzed data from Twitter to uncover early-warning signals of the coming COVID-19 pandemic in Europe. Whistleblowing came primarily from the geographical regions that eventually turned out to be the key breeding grounds for infections. So, start setting up an integrated digital surveillance system in which social media will geo-localize chains of contagion.

 

Virology

Calisher CH, Childs JE, Field HE, Holmes KV, Schountz T. Bats: important reservoir hosts of emerging viruses. Clin Microbiol Rev. 2006 Jul;19(3):531-45. PubMed: https://pubmed.gov/16847084. Full-text: https://doi.org/10.1128/CMR.00017-06

Bats – more than 1000 species, 25% of all recognized species of mammals; living in HUGE communities (ideal for viral spread); flying dozens of kilometers while searching for food. Bats – fast reactors for viral evolution? Never forget this 2006 primer for emerging infectious diseases.

 

Immunology

Takahashi T, Iwasaki A. Sex differences in immune responses. Science. 2021 Jan 22;371(6527):347-348. PubMed: https://pubmed.gov/33479140. Full-text: https://doi.org/10.1126/science.abe7199

Evidence increasingly indicates that male sex is a risk factor for more severe disease and death from COVID-19. Sex differences beyond sex organs are present across species and extend to physiological systems, including the immune system. Male sex in animals is more often associated with lower immune responses and higher susceptibility and/or vulnerability to infections. This is also generally the case in humans: male patients have higher viral loads for hepatitis B virus (HBV) and HIV.

 

Pathogenesis

Johnson BA, Xie X, Bailey AL, et al. Loss of furin cleavage site attenuates SARS-CoV-2 pathogenesis. Nature (2021). Full-text: https://doi.org/10.1038/s41586-021-03237-4

The authors generated a mutant SARS-CoV-2 deleting the furin cleavage site (ΔPRRA). SARS-CoV-2 ΔPRRA replicates had faster kinetics, improved fitness in Vero E6 cells, and reduced spike protein processing as compared to parental SARS-CoV-2. However, the ΔPRRA mutant had reduced replication in a human respiratory cell line and was attenuated in both hamster and K18-hACE2 transgenic mouse models of SARS-CoV-2 pathogenesis. The findings illustrate the critical role of the furin cleavage site in SARS-CoV-2 infection and pathogenesis. In its absence, the mutant ΔPRRA virus is attenuated in its ability to replicate in certain cell types and cause disease in vivo.

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