Omicron BQ.1.1 and XBB.1 unprecedentedly escape broadly neutralizing antibodies elicited by prototype vaccination.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariants have seriously attacked the antibody barrier established by natural infection and/or vaccination, especially the recently emerged BQ.1.1 and XBB.1. However, crucial mechanisms underlying the virus escape and the broad neutralization remain elusive. Here, we present a panoramic analysis of broadly neutralizing activity and binding epitopes of 75 monoclonal antibodies isolated from prototype inactivated vaccinees. Nearly all neutralizing antibodies (nAbs) partly or totally lose their neutralization against BQ.1.1 and XBB.1. We report a broad nAb, VacBB-551, that effectively neutralizes all tested subvariants including BA.2.75, BQ.1.1, and XBB.1. We determine the cryoelectron microscopy (cryo-EM) structure of VacBB-551 complexed with the BA.2 spike and perform detailed functional verification to reveal the molecular basis of N460K and F486V/S mutations mediating the partial escape of BA.2.75, BQ.1.1, and XBB.1 from the neutralization of VacBB-551. Overall, BQ.1.1 and XBB.1 raised the alarm over SARS-CoV-2 evolution with unprecedented antibody evasion from broad nAbs elicited by prototype vaccination.

Low concentration quaternary ammonium compounds promoted antibiotic resistance gene transfer via plasmid conjugation.

During the pandemic of COVID-19, the amounts of quaternary ammonium compounds (QACs) used to inactivate the virus in public facilities, hospitals and households increased, which raised concerns about the evolution and transmission of antimicrobial resistance (AMR). Although QACs may play an important role in the propagation of antibiotic resistance gene (ARGs), the potential contribution and mechanism remains unclear. Here, the results showed that benzyl dodecyl dimethyl ammonium chloride (DDBAC) and didecyl dimethyl ammonium chloride (DDAC) significantly promoted plasmid RP4-mediated ARGs transfer within and across genera at environmental relevant concentrations (0.0004-0.4 mg/L). Low concentrations of QACs did not contribute to the permeability of the cell plasma membrane, but significantly increased the permeability of the cell outer membrane due to the decrease in content of lipopolysaccharides. QACs altered the composition and content of extracellular polymeric substances (EPS) and were positively correlated with the conjugation frequency. Furthermore, transcriptional expression levels of genes encode for mating pairing formation (trbB), DNA replication and translocation (trfA), and global regulators (korA, korB, trbA) are regulated by QACs. And we demonstrate for the first time that QACs decreased the concentration of extracellular AI-2 signals, which was verified to be involved in regulating conjugative transfer genes (trbB, trfA). Collectively, our findings underscore the risk of increased disinfectant concentrations of QACs on the ARGs transfer and provide new mechanisms of plasmid conjugation.

Effect of surgical mask on fMRI signals during task and rest.

Wearing a face mask has become essential to contain the spread of COVID-19 and has become mandatory when collecting fMRI data at most research institutions. Here, we investigate the effects of wearing a surgical mask on fMRI data in n = 37 healthy participants. Activations during finger tapping, emotional face matching, working memory tasks, and rest were examined. Preliminary fMRI analyses show that despite the different mask states, resting-state signals and task activations were relatively similar. Resting-state functional connectivity showed negligible attenuation patterns in mask-on compared with mask-off. Task-based ROI analysis also demonstrated no significant difference between the two mask states under each contrast investigated. Notwithstanding the overall insignificant effects, these results indicate that wearing a face mask during fMRI has little to no significant effect on resting-state and task activations.

The Architecture of Inactivated SARS-CoV-2 with Postfusion Spikes Revealed by Cryo-EM and Cryo-ET.

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) resulted from the outbreak of SARS-CoV-2 in December 2019. Currently, multiple efforts are being made to rapidly develop vaccines and treatments to fight COVID-19. Current vaccine candidates use inactivated SARS-CoV-2 viruses; therefore, it is important to understand the architecture of inactivated SARS-CoV-2. We have genetically and structurally characterized ß-propiolactone-inactivated viruses from a propagated and purified clinical strain of SARS-CoV-2. We observed that the virus particles are roughly spherical or moderately pleiomorphic. Although a small fraction of prefusion spikes are found, most spikes appear nail shaped, thus resembling a postfusion state, where the S1 protein of the spike has disassociated from S2. Cryoelectron tomography and subtomogram averaging of these spikes yielded a density map that closely matches the overall structure of the SARS-CoV postfusion spike and its corresponding glycosylation site. Our findings have major implications for SARS-CoV-2 vaccine design, especially those using inactivated viruses.

Management and Reconfiguration of a Radiology Department under the Threat of Coronavirus Disease 2019: Experience from Wuhan.

The corona virus disease 2019 (COVID-19) is an emerging respiratory infectious disease caused by SARS-CoV-2, which first occurred in December 2019 in Wuhan, China. These days, in China, chest CT is used for diagnosis of COVID-19, as an important complement to the reverse-transcription polymerase chain reaction (RT-PCR) test. Because of contacting with a large number of suspected or probable cases closely during chest CT examination, radiographers are easily infected with COVID-19. This article included the rearrangement of CT examination room in fever clinic, the rearrangement of human resources in radiology department, and the drafting of new operating procedures for radiologists who carry out CT examination on COVID-19 patients. This article also introduced the emergency management procedures of the department of radiology during the outbreak, and the experience of infection prevention for the staff of the department of radiology.