Development of neutralizing antibodies against SARS-CoV-2, using a high-throughput single-B-cell cloning method.

Background: Rapid and efficient strategies are needed to discover neutralizing antibodies (nAbs) from B cells derived from virus-infected patients. Methods: Here, we report a high-throughput single-B-cell cloning method for high-throughput isolation of nAbs targeting diverse epitopes on the SARS-CoV-2-RBD (receptor binding domain) from convalescent COVID-19 patients. This method is simple, fast and highly efficient in generating SARS-CoV-2-neutralizing antibodies from COVID-19 patients' B cells. Results: Using this method, we have developed multiple nAbs against distinct SARS-CoV-2-RBD epitopes. CryoEM and crystallography revealed precisely how they bind RBD. In live virus assay, these nAbs are effective in blocking viral entry to the host cells. Conclusion: This simple and efficient method may be useful in developing human therapeutic antibodies for other diseases and next pandemic.

The Spatial-Temporal Evolution and Influencing Factors of Public Attention to 5G: Empirical Analysis Based on Baidu Index from 2011 to 2021

The development of 5G (fifth-generation wireless systems) determines the future direction of technology and economy and has received extensive public attention. Studying the changing rules of public attention to 5G can provide an important guiding significance for the sustainable development of 5G. This paper takes Baidu Index as the measurement index of 5G public attention and analyzes the spatial and temporal evolution characteristics and influencing factors of public attention to 5G from 2011 to 2021 by using the elasticity coefficient, Gini coefficient, geographical concentration index, and panel data model. The results of the study show the following. (1) The public concern to 5G is generally on the rise, but the heat has declined in the past two years. (2) The public's 5G attention shows a seasonal effect, with the highest attention in March and June. (3) The spatial difference of 5G public attention is obvious. The eastern region has a high degree of attention, the internal differences between the eastern and western regions are obvious, and the central region is relatively balanced. (4) The factors such as local economic level, education level, Internet development, and media attention have significantly affected the public focus on 5G. Also, some suggestions are made for the sustainable development of 5G and the planning of 6G (sixth-generation wireless systems).

Characterization of the enhanced infectivity and antibody evasion of Omicron BA.2.75.

Recently emerged SARS-CoV-2 Omicron subvariant, BA.2.75, displayed a growth advantage over circulating BA.2.38, BA.2.76, and BA.5 in India. However, the underlying mechanisms for enhanced infectivity, especially compared with BA.5, remain unclear. Here, we show that BA.2.75 exhibits substantially higher affinity for host receptor angiotensin-converting enzyme 2 (ACE2) than BA.5 and other variants. Structural analyses of BA.2.75 spike shows its decreased thermostability and increased frequency of the receptor binding domain (RBD) in the "up" conformation under acidic conditions, suggesting enhanced low-pH-endosomal cell entry. Relative to BA.4/BA.5, BA.2.75 exhibits reduced evasion of humoral immunity from BA.1/BA.2 breakthrough-infection convalescent plasma but greater evasion of Delta breakthrough-infection convalescent plasma. BA.5 breakthrough-infection plasma also exhibits weaker neutralization against BA.2.75 than BA.5, mainly due to BA.2.75's distinct neutralizing antibody (NAb) escape pattern. Antibody therapeutics Evusheld and Bebtelovimab remain effective against BA.2.75. These results suggest BA.2.75 may prevail after BA.4/BA.5, and its increased receptor-binding capability could support further immune-evasive mutations.

Characterization of the enhanced infectivity and antibody evasion of Omicron BA.2.75

Recently emerged SARS-CoV-2 Omicron subvariant, BA.2.75, displayed a growth advantage over circulating BA.2.38, BA.2.76 and BA.5 in India. However, the underlying mechanisms for enhanced infectivity, especially compared to BA.5, remain unclear. Here we show BA.2.75 exhibits substantially higher affinity for host receptor ACE2 than BA.5 and other variants. Structural analyses of BA.2.75 Spike shows its decreased thermostability and increased frequency of the receptor binding domain (RBD) in the “up” conformation under acidic conditions, suggesting enhanced low-pH-endosomal cell entry. Relative to BA.4/BA.5, BA.2.75 exhibits reduced evasion of humoral immunity from BA.1/BA.2 breakthrough-infection convalescent plasma, but greater evasion of Delta breakthrough-infection convalescent plasma. BA.5 breakthrough infection plasma also exhibits weaker neutralization against BA.2.75 than BA.5, mainly due to BA.2.75’s distinct neutralizing antibody escape pattern. Antibody therapeutics Evusheld and Bebtelovimab remain effective against BA.2.75. These results suggest BA.2.75 may prevail after BA.4/BA.5, and its increased receptor-binding capability could support further immune-evasive mutations. Graphical SARS-CoV-2 BA.2.75 is growing rapidly and globally. Cao et al. solved the structure of BA.2.75 spike and show it has stronger binding to human ACE2 than previous variants. BA.2.75 also exhibited distinct antigenicity compared to BA.5, escaping neutralizing antibodies targeting various epitopes and evading convalescent plasma from BA.5 breakthrough infections.

Development and Preliminary Validation of the Pandemic Avoidance and Concern Scales (PACS).

The COVID-19 pandemic has led to radical disruptions to the routines of individuals and families, but there are few psychometrically assessed measures for indexing behavioural responses associated with a modern pandemic. Given the likelihood of future pandemics, valid tools for assessing pandemic-related behavioral responses relevant to mental health are needed. This need may be especially salient for studies involving families, as they may experience higher levels of stress and maladjustment related to school and business closures. We therefore created the Pandemic Avoidance and Concern Scales (PACS) to assess caregivers' and youths' adjustment to COVID-19 and future pandemics. Concern and Avoidance factors derived from exploratory factor analyses were associated with measures of internalizing symptoms, as well as other indices of pandemic-related disruption. Findings suggest that the PACS is a valid tool for assessing pandemic-related beliefs and behaviors in adults and adolescents. Preliminary findings related to differential adjustment between caregivers and youths are discussed.

Neutralizing antibodies and cellular immune response after two doses of inactivated SARS-CoV-2 vaccine in China.

BACKGROUND: As of 2022, inactivated SARS-CoV-2 vaccines had been used in more than 91 countries. However, limited real world information was available on the immune responses of the inactivated SARS-CoV-2 vaccine. METHODS: We used SARS-CoV-2 pseudovirues to determine the neutralizing antibodies (NAbs) to wild type and several global variants and utilized enzyme-linked immunosorbent assay to investigate IFN-γ-secreting T-cell responses to SARS-CoV-2 among 240 vaccinated individuals after two doses of inactivated vaccine in China. RESULTS: A majority of the vaccinated (>90%) developed robust NAbs and T-cell responses to SARS-CoV-2 in the first two months after the second dose. After six months, only 37.0% and 44.0% of vaccinees had NAbs and T-cell immunity to SARS-CoV-2, respectively. Immune serum retained most of its neutralizing potency against the Alpha and Iota variants, but lost significant neutralizing potency against the Beta, Kappa, Delta, and Omicron variants. Only 40% of vaccine-sera retained low-level neutralization activities to Omicron, with a 14.7-fold decrease compared to the wild type. CONCLUSION: The inactivated SARS-CoV-2 vaccine stimulated robust NAbs and T-cell immune responses in the first two months after the second dose but the immune effect dropped rapidly, highlighing that a third dose or additional booster immunizations may be required to boost immunity against SARS-CoV-2.

Can SARS-CoV-2 positive pregnant women affect the hearing of their newborns: A systematic review.

The 2019 coronavirus disease (COVID-19) pandemic has caused over 500 million confirmed cases (including pregnant women) worldwide. Recently, hearing status in newborns born to mothers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has received attention. This systematic review outlines the current knowledge regarding the effects of maternal SARS-CoV-2 infection during pregnancy on newborn hearing. Intrauterine SARS-CoV-2 infection has the potential to affect the auditory system of the newborn due to intrauterine hypoxia and vertical transmission. SARS-CoV-2 might have a greater influence on hearing loss (HL) in newborns during the second and third trimesters of pregnancy. Therefore, all newborns whose mothers had COVID-19 during pregnancy should be evaluated for cochlear function, regardless of whether their mothers were symptomatic at the time of the disease. However, the understanding of this issue is not consistent and remains controversial. Since early identification and intervention of congenital HL are crucial to the language development of newborns, newborns should be provided with audiological evaluation by various approaches, including Tele-audiology, in the COVID-19 era.

Neutralizing Antibodies and Cellular Immune Responses Against SARS-CoV-2 Sustained One and a Half Years After Natural Infection.

Background: COVID-19 has caused more than 2.6 billion infections and several million deaths since its outbreak 2 years ago. We know very little about the long-term cellular immune responses and the kinetics of neutralizing antibodies (NAbs) to SARS-CoV-2 because it has emerged only recently in the human population. Methods: We collected blood samples from individuals who were from the first wave of the COVID-19 epidemic in Wuhan between December 30, 2019, and February 24, 2020. We analyzed NAbs to SARS-CoV-2 using pseudoviruses and IgG antibodies to SARS-CoV-2 spike (S) and nucleocapsid (N) protein using enzyme-linked immunosorbent assay in patients' sera and determined SARS-CoV-2-specific T-cell responses of patients with ELISpot assays. Results: We found that 91.9% (57/62) and 88.9% (40/45) of COVID-19 patients had NAbs against SARS-CoV-2 in a year (10-11 months) and one and a half years (17-18 months), respectively, after the onset of illness, indicating that NAbs against SARS-CoV-2 waned slowly and possibly persisted over a long period time. Over 80% of patients had IgG antibodies to SARS-CoV-2 S and N protein one and a half years after illness onset. Most patients also had robust memory T-cell responses against SARS-CoV-2 one and a half years after the illness. Among the patients, 95.6% (43/45) had an IFN-γ-secreting T-cell response and 93.8% (15/16) had an IL-2-secreting T-cell response. The T-cell responses to SARS-CoV-2 were positively correlated with antibodies (including neutralizing antibodies and IgG antibodies to S and N protein) in COVID-19 patients. Eighty percent (4/5) of neutralizing antibody-negative patients also had SARS-CoV-2-specific T-cell response. After long-term infection, protective immunity was independent of disease severity, sex, and age. Conclusions: We concluded that SARS-CoV-2 infection elicited a robust and persistent neutralizing antibody and memory T-cell response in COVID-19 patients, indicating that these sustained immune responses, among most SARS-CoV-2-infected people, may play a crucial role in protection against reinfection.

Memory B cell repertoire from triple vaccinees against diverse SARS-CoV-2 variants.

Omicron (B.1.1.529), the most heavily mutated SARS-CoV-2 variant so far, is highly resistant to neutralizing antibodies, raising concerns about the effectiveness of antibody therapies and vaccines1,2. Here we examined whether sera from individuals who received two or three doses of inactivated SARS-CoV-2 vaccine could neutralize authentic Omicron. The seroconversion rates of neutralizing antibodies were 3.3% (2 out of 60) and 95% (57 out of 60) for individuals who had received 2 and 3 doses of vaccine, respectively. For recipients of three vaccine doses, the geometric mean neutralization antibody titre for Omicron was 16.5-fold lower than for the ancestral virus (254). We isolated 323 human monoclonal antibodies derived from memory B cells in triple vaccinees, half of which recognized the receptor-binding domain, and showed that a subset (24 out of 163) potently neutralized all SARS-CoV-2 variants of concern, including Omicron. Therapeutic treatments with representative broadly neutralizing monoclonal antibodies were highly protective against infection of mice with SARS-CoV-2 Beta (B.1.351) and Omicron. Atomic structures of the Omicron spike protein in complex with three classes of antibodies that were active against all five variants of concern defined the binding and neutralizing determinants and revealed a key antibody escape site, G446S, that confers greater resistance to a class of antibodies that bind on the right shoulder of the receptor-binding domain by altering local conformation at the binding interface. Our results rationalize the use of three-dose immunization regimens and suggest that the fundamental epitopes revealed by these broadly ultrapotent antibodies are rational targets for a universal sarbecovirus vaccine.

Structural and functional characterizations of infectivity and immune evasion of SARS-CoV-2 Omicron.

The SARS-CoV-2 Omicron variant with increased fitness is spreading rapidly worldwide. Analysis of cryo-EM structures of the spike (S) from Omicron reveals amino acid substitutions forging interactions that stably maintain an active conformation for receptor recognition. The relatively more compact domain organization confers improved stability and enhances attachment but compromises the efficiency of the viral fusion step. Alterations in local conformation, charge, and hydrophobic microenvironments underpin the modulation of the epitopes such that they are not recognized by most NTD- and RBD-antibodies, facilitating viral immune escape. Structure of the Omicron S bound with human ACE2, together with the analysis of sequence conservation in ACE2 binding region of 25 sarbecovirus members, as well as heatmaps of the immunogenic sites and their corresponding mutational frequencies, sheds light on conserved and structurally restrained regions that can be used for the development of broad-spectrum vaccines and therapeutics.

Efficacy of Chinese Herbal Injections for Elderly Patients With pneumonia-A Bayesian Network Meta-analysis of Randomized Control Trials.

Background: Pneumonia is a prevalent and complicated disease among adults, elderly people in particular, and the debate on the optimal Chinese herbal injections (CHIs) is ongoing. Our objective is to investigate the comparative effectiveness of various CHIs strategies for elderly patients with pneumonia. Methods: A comprehensive search strategy was executed to identify relevant randomized controlled trials (RCTs) by browsing through several databases from their inception to first, Feb 2020; All of the direct and indirect evidence included was rated by Network meta-analysis under a Bayesian framework. Results: We ultimately identified 34 eligible randomized controlled trials that involved 3,111 elderly participants and investigated 4 CHIs combined with Western medicine (WM) (Xiyanping injection [XYP]+WM, Yanhuning injection [YHN]+WM, Tanreqing injection [TRQ]+WM, Reduning injection [RDN]+WM), contributing 34 direct comparisons between CHIs. Seen from the outcome of Clinical effective rate and time for defervescence, patients taking medicine added with CHIs [Clinical effective rate, XYP + WM(Odd ratio (OR): 0.74, 95%Credible intervals (CrIs):0.55-0.98), YHN + WM(OR: 0.66, 95%CrI: 0.45-0.95), TRQ + WM(OR: 0.65, 95%CrI: 0.50-0.83), RDN + WM(OR: 0.60, 95%CrI: 0.40-0.89); Time for defervescence, YHN + WM(Mean difference (MD): -2.11, 95%CrI: -3.26 to -0.98), XYP + WM(MD: -2.06, 95%CrI: -3.08 to -1.09), RDN + WM(MD: -1.97, 95%CrI: -3.61 to -0.35), TRQ + WM(MD: -1.69, 95%CrI: -2.27 to -1.04)] showed statistically better effect compared with participants in the Control group (CG) who only took WM. Meanwhile, based on the time for disappearance of cough, 3 out of 4 CHIs [TRQ + WM(MD: -2.56, 95%CrI: -3.38 to -1.54), YHN + WM(MD: -2.36, 95%CrI: -3.86 to -1.00) and XYP + WM(MD: -2.21, 95%CrI: -3.72 to -1.10)] strategies indicated improvement of clinical symptoms. Only XYP + WM(MD -1.78, 95%CrI: -3.29 to -0.27) and TRQ + WM (MD: -1.71, 95%CrI: -2.71 to -0.73) could significantly shorten the time for disappearance of pulmonary rales. Conclusion: According to the statistical effect size (The surface under the cumulative ranking), we found that XYP + WM was presumably to be the preferable treatment for treating elderly patients with pneumonia compared with WM alone in terms of clinical effective rate. Our findings were based on very limited evidence and thus should be interpreted with caution. The application of the findings requires further research.

Classification of COVID-19 Chest CT Images Based on Ensemble Deep Learning.

Novel coronavirus pneumonia (NCP) has become a global pandemic disease, and computed tomography-based (CT) image analysis and recognition are one of the important tools for clinical diagnosis. In order to assist medical personnel to achieve an efficient and fast diagnosis of patients with new coronavirus pneumonia, this paper proposes an assisted diagnosis algorithm based on ensemble deep learning. The method combines the Stacked Generalization ensemble learning with the VGG16 deep learning to form a cascade classifier, and the information constituting the cascade classifier comes from multiple subsets of the training set, each of which is used to collect deviant information about the generalization behavior of the data set, such that this deviant information fills the cascade classifier. The algorithm was experimentally validated for classifying patients with novel coronavirus pneumonia, patients with common pneumonia (CP), and normal controls, and the algorithm achieved a prediction accuracy of 93.57%, sensitivity of 94.21%, specificity of 93.93%, precision of 89.40%, and F1-score of 91.74% for the three categories. The results show that the method proposed in this paper has good classification performance and can significantly improve the performance of deep neural networks for multicategory prediction tasks.

Development of a Nucleocapsid Protein-Based ELISA for Detection of Human IgM and IgG Antibodies to SARS-CoV-2.

SARS-CoV-2 is the etiologic agent of COVID-19, which has led to a dramatic loss of human life and presents an unprecedented challenge to public health worldwide. The gold standard assay for SARS-CoV-2 identification is real-time polymerase chain reaction; however, this assay depends on highly trained personnel and sophisticated equipment and may suffer from false results. Thus, a serological antibody test is a supplement to the diagnosis or screening of SARS-CoV-2. Here, we develop and evaluate the diagnostic performance of an IgM/IgG indirect ELISA method for antibodies against SARS-CoV-2 in COVID-19. The ELISA was constructed by coating with a recombinant nucleocapsid protein of SARS-CoV-2 on an enzyme immunoassay plate, and its sensitivity and specificity for clinical diagnosis of SARS-CoV-2 infection was assessed by detecting the SARS-CoV-2-specific IgM and IgG antibodies in COVID-19 patient's sera or healthy person's sera. The SARS-CoV-2 positive serum samples (n = 168) were collected from confirmed COVID-19 patients. A commercial nucleocapsid protein-based chemiluminescent immunoassay (CLIA) kit and a colloidal gold immunochromatography kit were compared with those of the ELISA assay. The specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of IgM were 100, 95.24, 100, and 91.84%, whereas those of IgG were 100, 97.02, 100, and 94.74%, respectively. We developed a highly sensitive and specific SARS-CoV-2 nucleocapsid protein-based ELISA method for the diagnosis and epidemiologic investigation of COVID-19 by SARS-CoV-2 IgM and IgG antibody detection.

Classification of COVID-19 pneumonia from chest CT images based on reconstructed super-resolution images and VGG neural network.

The COVID-19 coronavirus has spread rapidly around the world and has caused global panic. Chest CT images play a major role in confirming positive COVID-19 patients. The computer aided diagnosis of COVID-19 from CT images based on artificial intelligence have been developed and deployed in some hospitals. But environmental influences and the movement of lung will affect the image quality, causing the lung parenchyma and pneumonia area unclear in CT images. Therefore, the performance of COVID-19's artificial intelligence diagnostic algorithm is reduced. If chest CT images are reconstructed, the accuracy and performance of the aided diagnostic algorithm may be improved. In this paper, a new aided diagnostic algorithm for COVID-19 based on super-resolution reconstructed images and convolutional neural network is presented. Firstly, the SRGAN neural network is used to reconstruct super-resolution images from original chest CT images. Then COVID-19 images and Non-COVID-19 images are classified from super-resolution chest CT images by VGG16 neural network. Finally, the performance of this method is verified by the pubic COVID-CT dataset and compared with other aided diagnosis methods of COVID-19. The experimental results show that improving the data quality through SRGAN neural network can greatly improve the final classification accuracy when the data quality is low. This proves that this method can obtain high accuracy, sensitivity and specificity in the examined test image datasets and has similar performance to other state-of-the-art deep learning aided algorithms.

Assisting scalable diagnosis automatically via CT images in the combat against COVID-19.

The pandemic of Coronavirus Disease 2019 (COVID-19) is causing enormous loss of life globally. Prompt case identification is critical. The reference method is the real-time reverse transcription PCR (RT-PCR) assay, whose limitations may curb its prompt large-scale application. COVID-19 manifests with chest computed tomography (CT) abnormalities, some even before the onset of symptoms. We tested the hypothesis that the application of deep learning (DL) to 3D CT images could help identify COVID-19 infections. Using data from 920 COVID-19 and 1,073 non-COVID-19 pneumonia patients, we developed a modified DenseNet-264 model, COVIDNet, to classify CT images to either class. When tested on an independent set of 233 COVID-19 and 289 non-COVID-19 pneumonia patients, COVIDNet achieved an accuracy rate of 94.3% and an area under the curve of 0.98. As of March 23, 2020, the COVIDNet system had been used 11,966 times with a sensitivity of 91.12% and a specificity of 88.50% in six hospitals with PCR confirmation. Application of DL to CT images may improve both efficiency and capacity of case detection and long-term surveillance.

Brief Report: Virologic and Immunologic Outcomes for HIV Patients With Coronavirus Disease 2019.

BACKGROUND: To describe the virologic and immunologic outcomes among people living with HIV (PLHIV) coinfected with SARS-CoV-2. SETTING: Wuhan, China. METHODS: Thirty-five coinfected patients were identified by matching the reported cases in National Notifiable Infectious Disease Report system for COVID-19 and HIV in Wuhan by time of April 19, 2020. Questionnaire-based survey and follow-up with blood sample collection were used to obtain characteristics before COVID-19 and after recovery. Nonparametric Mann-Whitney U test, χ2, or Fisher exact test, Mcnemar test, and Wilcoxon test were conducted. RESULTS: Twenty of the 35 coinfected patients were identified as asymptomatic/mild/moderate COVID-19 (nonsevere group) and 15 were identified as severe/critical (severe group). The severe and nonsevere group had no differences in demographics, HIV baseline status, the intervals between last tests and follow-up tests for CD4+ cell count and HIV-1 viral load (all P > 0.05). Overall, there was a significantly increased number of coinfected patients with HIV-1 viral load ≥20 copies/mL after recovery (P = 0.008). The median viral load increased significantly after recovery in severe group (P = 0.034), whereas no significant change of HIV-1 viral load was observed in the nonsevere group. Limited change of CD4+ cell count was found (all P > 0.05). CONCLUSION: The coinfection of SARS-CoV-2 may put PLHIV at greater risk for HIV-1 viral rebound especially for severe/critical COVID-19, whereas it had limited impacts on CD4+ cell count. Whether continuous antiretroviral therapy against HIV infection would have significant impacts on CD4+ cell count among PLHIV coinfected with SARS-CoV-2 needs further research.

Designed variants of ACE2-Fc that decouple anti-SARS-CoV-2 activities from unwanted cardiovascular effects.

Angiotensin-converting enzyme 2 (ACE2) is the entry receptor for SARS-CoV-2, and recombinant ACE2 decoys are being evaluated as new antiviral therapies. We designed and tested an antibody-like ACE2-Fc fusion protein, which has the benefit of long pharmacological half-life and the potential to facilitate immune clearance of the virus. Out of a concern that the intrinsic catalytic activity of ACE2 may unintentionally alter the balance of its hormonal substrates and cause adverse cardiovascular effects in treatment, we performed a mutagenesis screening for inactivating the enzyme. Three mutants, R273A, H378A and E402A, completely lost their enzymatic activity for either surrogate or physiological substrates. All of them remained capable of binding SARS-CoV-2 and could suppress the transduction of a pseudotyped virus in cell culture. This study established new ACE2-Fc candidates as antiviral treatment for SARS-CoV-2 without potentially harmful side effects from ACE2's catalytic actions toward its vasoactive substrates.

Does Distance Produce Beauty? The Influence of COVID-19 Lockdown on the Coach-Athlete Relationship in a Chinese Football School.

This paper examined the relationship between coaches and youth athletes in China by comparing data collected before and after the lockdown. A total of 221 youth athletes aged 13-19 years in one professional football school completed coach-athlete relationship questionnaires. The rank-sum test was used to verify the differences in the data. The results of the Mann-Whitney U test showed that mean value of the three dimensions of the coach-athlete relationship (closeness, commitment, and complementarity) increased after the COVID-19 lockdown. The results also showed that athletes of different age categories showed different changes in the coach-athlete relationship after the lockdown, and the changes were not significantly related to the severity of the COVID-19 epidemic. The theoretical and practical implications are discussed.