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Genetic and testing data from England show that the SARS-CoV-2 variant of concern B.1.1.7 has a transmission advantage over other lineages.

This work shows how to connect a fibre to a single-photon source based on quantum dots in microcavities. The alignment relies on reflectivity measurements. The structure is stable from room to cryogenic temperature and over several cooling cycles.

Quantum-correlated photons typically characterize strongly nonlinear quantum emitters. A two-photon correlation spectroscopy method now provides a powerful probe of weakly nonlinear many-body quantum systems.

Post-international travel quarantine has been widely implemented to mitigate SARS-CoV-2 transmission, but the impacts of such policies are unclear. Here, the authors used linked genomic and contact tracing data to assess the impacts of a 14-day quarantine on return to England in summer 2020.

A study of the evolution of the SARS-CoV-2 virus in England between September 2020 and June 2021 finds that interventions capable of containing previous variants were insufficient to stop the more transmissible Alpha and Delta variants.

Previously, superradiance was observed from sizeable crystals or close to liquid-helium temperatures. Here, Bradec et al. report the observation of room-temperature superradiance from single, highly luminescent diamond nanocrystals with spatial dimensions much smaller than the wavelength of light.

This Registered Report presents evidence from 87 countries and regions showing that brief emotion-regulation interventions consistently reduced negative emotions and increased positive emotions during the COVID-19 pandemic.

In this study, Aggarwal and colleagues perform prospective sequencing of SARS-CoV-2 isolates derived from asymptomatic student screening and symptomatic testing of students and staff at the University of Cambridge. They identify important factors that contributed to within university transmission and onward spread into the wider community.

Chronic infection with SARS-CoV-2 leads to the emergence of viral variants that show reduced susceptibility to neutralizing antibodies in an immunosuppressed individual treated with convalescent plasma.

Sera from vaccinated individuals and some monoclonal antibodies show a modest reduction in neutralizing activity against the B.1.1.7 variant of SARS-CoV-2; but the E484K substitution leads to a considerable loss of neutralizing activity.

HEV-specific antiviral treatment is still lacking. Here, the authors functionally and structurally characterize broadly neutralizing antibodies isolated from HEV convalescent individuals and show that they have protective effects in human liver-chimeric mice infected with HEV.

Researchers observe a continuous change in photon correlations from strong antibunching to bunching by tuning either the probe laser or the cavity mode frequency. These results, which demonstrate unprecedented strong single-photon nonlinearities in quantum dot cavity system, are explained by the photon blockade and tunnelling in the anharmonic Jaynes–Cummings model.

The Omicron variant evades vaccine-induced neutralization but also fails to form syncytia, shows reduced replication in human lung cells and preferentially uses a TMPRSS2-independent cell entry pathway, which may contribute to enhanced replication in cells of the upper airway. Altered fusion and cell entry characteristics are linked to distinct regions of the Omicron spike protein.

We uncover key processes of the genomic evolution of small cell lung cancer under therapy, identify the common ancestor as the source of clonal diversity at relapse and show central genomic patterns associated with drug response.

Researchers report the first demonstration of an ultrafast all-optical switch in the single-photon regime. The device, which consists of an InAs/GaAs quantum dot in a photonic crystal defect cavity, exhibits a coherent coupling constant of 141 meV and a quality factor of 25,000. The overall switching time is around 50 ps.

Cu₂O is a promising platform to host Rydberg exciton–polaritons, where excitons strongly couple to cavity photons, however their realization has been elusive. Here, the authors report Rydberg exciton–polaritons with principal quantum numbers up to n = 6.

The COVID-19 pandemic has been characterised by periods of dominance of different SARS-CoV-2 variants. In this mathematical modelling study, the authors investigate the epidemiological properties of successive variants in England until early 2022 and quantify the impacts of control measures.

Analysis of SARS-CoV-2 genomes from around the world show that following initial importation largely from India, Delta spread in England was driven first by inter-regional travel and then by local population mixing.

In a clinical trial, Fathi et al. show that a booster vaccination with a vector vaccine candidate against the highly pathogenic Middle East Respiratory Syndrome coronavirus is safe and strongly improves the immunity generated by primary immunization.

Spatiotemporal regulation of wound healing in mice and humans occurs via retinoic acid and hypoxia signalling, which regulate the differentiation of CD201⁺ fibroblast progenitors into proinflammatory and myofibroblast states.

Extensive scars develop in deep wounds as opposed to superficial wounds but it is unclear why. Here, the authors use live imaging of physiologic wounds and scars formed ex vivo to show that fascia fibroblasts upregulate N-cadherin allowing coordinated cell migration that drives extensive scar formation of deep wounds.

Cells that populate scar tissue in mammalian skin migrate to wounds as prefabricated matrix from the subcutaneous fascia, including embedded blood vessels, macrophages and peripheral nerves.

Here Jeskeet al. show both theoretical and experimental evidence for stimulated emission from negatively charged nitrogen vacancy centres using light in the phonon sidebands around 700 nm, demonstrating its suitability as a laser medium.

Social distancing policies aiming to reduce COVID-19 transmission have been reflected in reductions in human mobility. Here, the authors show that reduced mobility is correlated with decreased transmission, but that this relationship weakened over time as social distancing measures were relaxed.

Blockade of intrahepatic accumulation and function of platelets represents a potential approach to treat non-alcoholic steatohepatitis (NASH) and prevent subsequent progression to hepatocellular carcinoma

Modelling based on pooled data from 11 European countries indicates that non-pharmaceutical interventions—particularly lockdowns—have had a marked effect on SARS-CoV-2 transmission, driving the reproduction number of the infection below 1.

The World Health Organization framework for tracking SARS-CoV-2 variants has been updated to reflect the continued evolution of the virus; this framework could be adapted for other emerging respiratory diseases with epidemic and pandemic potential.

Spinal cord injury causes life-threatening infections. The authors report that this is partially mediated by a maladaptive neuroendocrine reflex, extending from the spinal cord to the adrenal glands, where it blocks catecholamines while producing immunosuppressive corticosteroids. The effect depends on the spinal injury level, and normalization of hormones production by the adrenals rescued mice from pneumonia.

Two-photon correlation measurements in a resonantly excited fibre-cavity polariton system stay below the classical limit for zero time delay, suggesting quantum correlations between the polaritons.

The strength of optical trapping of a nanodiamond can be increased by cooperative effects between its numerous colour centres — or artificial atoms: an observation that brings together ideas from atom and nanoparticle trapping.

Global sequencing and surveillance capacity for SARS-CoV-2 must be strengthened and combined with multidisciplinary studies of infectivity, virulence and immune escape, in order to track the unpredictable evolution of the ongoing COVID-19 pandemic.

Inhibiting virus cell entry by targeting tight junctions cures HCV infection in mice.