Stability of SARS-CoV-2 and persistence of viral nucleic acids on common foods and widely used packaging material surfaces.

SARS-CoV-2 is still spreading globally. Studies have reported the stability of SARS-CoV-2 in aerosols and on surfaces under different conditions. However, studies on the stability of SARS-CoV-2 and viral nucleic acids on common food and packaging material surfaces are insufficient. The study evaluated the stability of SARS-CoV-2 using TCID50 assays and the persistence of SARS-CoV-2 nucleic acids using droplet digital polymerase chain reaction on various food and packaging material surfaces. Viral nucleic acids were stable on food and material surfaces under different conditions. The viability of SARS-CoV-2 varied among different surfaces. SARS-CoV-2 was inactivated on most food and packaging material surfaces within 1 day at room temperature but was more stable at lower temperatures. Viruses survived for at least 1 week on pork and plastic at 4°C, while no viable viruses were detected on hairtail, orange, or carton after 3 days. There were viable viruses and a slight titer decrease after 8 weeks on pork and plastic, but titers decreased rapidly on hairtail and carton at -20°C. These results highlight the need for targeted preventive and disinfection measures based on different types of foods, packaging materials, and environmental conditions, particularly in the cold-chain food trade, to combat the ongoing pandemic.

Accelerating Biosafety Capacity Building to Ensure National Biosecurity

Biosafety is an essential part of the national security system, which is related to people's lives and health, the country's longterm stability, and sustainable development, which is the bottom line that must be guaranteed. The international biosafety situation is grim and complex, while domestic biosafety faces challenges. Therefore, biosafety capacity building has become an international hot spot, among which scientific and technological innovation, talent training, and infrastructure platform construction are the top priorities. Although China has achieved strategic results in the rapid identification of pathogens, research, and development of specific vaccines and medicine in fighting against COVID-19 by relying on scientific research, it has shown the urgency for scientific and technological innovation in biosafety. Therefore,China has developed a strategic plan on "promoting the modernization of the national security system and capabilities, resolutely safeguarding national security and social stability" included in the 20th National Congress of the Communist Party of China. Hence, it is suggested to promote biosafety capacity building further to improve China's biosecurity system, protect people's health, ensure national security, and maintain long-term peace and stability by improving the layout of scientific and technological frontiers, promoting the construction of biosafety discipline, training of more special talents, and infrastructure platform construction.

Age-related rhesus macaque models of COVID-19.

BACKGROUND: Since December 2019, an outbreak of the Corona Virus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) in Wuhan, China, has become a public health emergency of international concern. The high fatality of aged cases caused by SARS-CoV-2 was a need to explore the possible age-related phenomena with non-human primate models. METHODS: Three 3-5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS-CoV-2, and then analyzed by clinical signs, viral replication, chest X-ray, histopathological changes and immune response. RESULTS: Viral replication of nasopharyngeal swabs, anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS-CoV-2 challenge. Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema, notably, old monkeys exhibited diffuse severe interstitial pneumonia. Viral antigens were detected mainly in alveolar epithelial cells and macrophages. CONCLUSION: SARS-CoV-2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys. Rhesus macaque models infected with SARS-CoV-2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS-CoV-2 infection.

Mental health and fatigue status of the medical workforce during the COVID-19 outbreak in the Yangzhou city, China.

Background: When the coronavirus disease 2019 (COVID-19) erupted in Yangzhou, China, at the end of July 2021, medical workers in Yangzhou immediately joined the frontline for the fight against the pandemic. This study aimed to identify the mental health and fatigue experienced by the medical workers in Yangzhou during the COVID-19 outbreak. Methods: We included 233 medical workers who participated in the front-line work for more than 1 month through the questionnaire, including doctors, nurses, medical technicians and medical students. The generalized anxiety disorder-7 (GAD-7), patient health questionnaire-9 (PHQ-9), and Fatigue self-assessment scale (FSAS) were administered to the participants and their responses were evaluated. Results: A total of 233 eligible questionnaires were received. Among them, 130 people (57.08%) were probably anxious and 141 (60.52%) people were clinically depressed. Poor sleep was considered an independent risk factor for anxiety (OR = 7.164, 95% CI: 3.365 15.251, p = 0.000) and depression (OR = 6.899, 95% CI: 3.392 14.030, p = 0.000). A high PHQ-9 score was considered an independent risk factor for general fatigue (OR = 1.697, 95% CI: 1.481 1.944, p = 0.000). Mental fatigue (OR = 1.092, 95% CI: 1.027 1.161, p = 0.005) and fatigue response to sleep/rest (OR = 1.043, 95% CI: 1.011 1.076 p = 0.008) were considered independent risk factors for general fatigue. Conclusion: Poor quality of sleep led to probable anxiety, depression, and general fatigue. Mental fatigue and fatigue response to sleep/rest were independent risk factors for depression, which merits attention for battling COVID-19.

Surveillance of SARS-CoV-2 at the Huanan Seafood Market.

SARS-CoV-2, the causative agent of COVID-19, emerged in December 2019. Its origins remain uncertain. It has been reported that a number of the early human cases had a history of contact with the Huanan Seafood Market. Here we present the results of surveillance for SARS-CoV-2 within the market. From January 1st 2020, after closure of the market, 923 samples were collected from the environment. From 18th January, 457 samples were collected from 18 species of animals, comprising of unsold contents of refrigerators and freezers, swabs from stray animals, and the contents of a fish tank. Using RT-qPCR, SARS-CoV-2 was detected in 73 environmental samples, but none of the animal samples. Three live viruses were successfully isolated. The viruses from the market shared nucleotide identity of 99.99% to 100% with the human isolate HCoV-19/Wuhan/IVDC-HB-01/2019. SARS-CoV-2 lineage A (8782T and 28144C) was found in an environmental sample. RNA-seq analysis of SARS-CoV-2 positive and negative environmental samples showed an abundance of different vertebrate genera at the market. In summary, this study provides information about the distribution and prevalence of SARS-CoV-2 in the Huanan Seafood Market during the early stages of the COVID-19 outbreak.

The effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on ischemic stroke and the possible underlying mechanisms.

Purpose: As of November 28, 2020, COVID-19 has been reported in 220 countries with 61,036,793 confirmed cases and 1,433,316 confirmed deaths; countries became vigilant around the world. In addition to SARS-CoV-2 causing pneumonia, many studies have reported ischemic stroke in patients with COVID-19. This article describes the effects and possible underlying mechanisms of SARS-CoV-2 on ischemic stroke.Materials and methods: A literature search was performed using PubMed, Web of Science, and other COVID-dedicated databases and the combination of the keywords 'SARS-CoV-2', 'COVID-19' and 'ischemic stroke' up to November 28, 2020.Results: SARS-CoV-2 invades the host through angiotensin converting enzyme 2 (ACE2). ACE2 is expressed not only in the lungs, but also in the brain and vascular endothelial cells. SARS-CoV-2 infection might cause direct vascular disease or enhance the immunogenic thrombosis environment through several mechanisms. SARS-CoV-2 infection can modulate the host immune response and can cause inflammation, coagulation disorders, renin angiotensin system disorders, hypoxia, and stress disorders, which may lead to the occurrence of ischemic stroke.Conclusions: Some patients with COVID-19 can develop ischemic stroke. Ischemic stroke has a high risk of causing disability and is associated with a high mortality rate. It is hoped that when medical staff treat patients with COVID-19, they would pay attention to the occurrence of ischemic stroke to improve the prognosis of patients with COVID-19.

Effect of COVID-19 vaccination on semen parameters: A systematic review and meta-analysis.

The aim of this study was to investigate the effect of coronavirus disease 2019 (COVID-19) vaccination on semen parameters through systematic review and meta-analysis. PubMed, EMBASE, Web of Science, and Cochrane Library were comprehensively searched by June 2022. Studies were considered eligible if they compared semen parameters before and after COVID-19 vaccination or between vaccinated and unvaccinated men, with no restrictions on vaccine types or doses. The effect size was calculated as mean difference (MD) with 95% confidence interval (CI) using a random-effects model. Subgroup and sensitivity analyses were conducted to assess the sources of heterogeneity measured by the I2 statistic, with publication bias evaluated by Egger's test. Twelve cohort studies involving 914 participants fulfilled the inclusion criteria. In a comparison of vaccinated versus unvaccinated group, the pooled data revealed no significant differences in semen volume (MD = 0.18 ml, 95% CI -0.02 to 0.38), sperm concentration (MD = 1.16 million/ml, 95% CI -1.34 to 3.66), total sperm motility (MD = -0.14%, 95% CI -2.84 to 2.56), progressive sperm motility (MD = -1.06%, 95% CI -2.88 to 0.77), total sperm count (MD = 5.92 million, 95% CI -10.22 to 22.05), total motile sperm count (MD = 2.18 million, 95% CI -1.28 to 5.63), total progressively motile sperm count (MD = -3.87 million, 95% CI -13.16 to 5.43), and sperm morphology (MD = 0.07%, 95% CI -0.84 to 0.97). The results also remained similar across messenger ribonucleic acid, viral-vector, and inactivated COVID-19 vaccines. Sensitivity analysis identified two individual studies that contributed to heterogeneity, while the effect size was not materially altered. No obvious publication bias was detected among included studies. Our finding suggested that COVID-19 vaccination had no detrimental impact on semen quality, which could be potentially helpful to reduce male vaccine hesitancy and increase vaccination coverage.

Immune response and homeostasis mechanism following administration of BBIBP-CorV SARS-CoV-2 inactivated vaccine.

The BBIBP-CorV severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccine has been authorized for emergency use and widely distributed. We used single-cell transcriptome sequencing to characterize the dynamics of immune responses to the BBIBP-CorV inactivated vaccine. In addition to the expected induction of humoral immunity, we found that the inactivated vaccine induced multiple, comprehensive immune responses, including significantly increased proportions of CD16+ monocytes and activation of monocyte antigen presentation pathways; T cell activation pathway upregulation in CD8+ T cells, along with increased activation of CD4+ T cells; significant enhancement of cell-cell communications between innate and adaptive immunity; and the induction of regulatory CD4+ T cells and co-inhibitory interactions to maintain immune homeostasis after vaccination. Additionally, comparative analysis revealed higher neutralizing antibody levels, distinct expansion of naive T cells, a shared increased proportion of regulatory CD4+ T cells, and upregulated expression of functional genes in booster dose recipients with a longer interval after the second vaccination. Our research will support a comprehensive understanding of the systemic immune responses elicited by the BBIBP-CorV inactivated vaccine, which will facilitate the formulation of better vaccination strategies and the design of new vaccines.

Mental health and fatigue status of the medical workforce during the COVID-19 outbreak in the Yangzhou city, China

Background When the coronavirus disease 2019 (COVID-19) erupted in Yangzhou, China, at the end of July 2021, medical workers in Yangzhou immediately joined the frontline for the fight against the pandemic. This study aimed to identify the mental health and fatigue experienced by the medical workers in Yangzhou during the COVID-19 outbreak. Methods We included 233 medical workers who participated in the front-line work for more than 1 month through the questionnaire, including doctors, nurses, medical technicians and medical students. The generalized anxiety disorder-7 (GAD-7), patient health questionnaire-9 (PHQ-9), and Fatigue self-assessment scale (FSAS) were administered to the participants and their responses were evaluated. Results A total of 233 eligible questionnaires were received. Among them, 130 people (57.08%) were probably anxious and 141 (60.52%) people were clinically depressed. Poor sleep was considered an independent risk factor for anxiety (OR = 7.164, 95% CI: 3.365 15.251, p = 0.000) and depression (OR = 6.899, 95% CI: 3.392 14.030, p = 0.000). A high PHQ-9 score was considered an independent risk factor for general fatigue (OR = 1.697, 95% CI: 1.481 1.944, p = 0.000). Mental fatigue (OR = 1.092, 95% CI: 1.027 1.161, p = 0.005) and fatigue response to sleep/rest (OR = 1.043, 95% CI: 1.011 1.076 p = 0.008) were considered independent risk factors for general fatigue. Conclusion Poor quality of sleep led to probable anxiety, depression, and general fatigue. Mental fatigue and fatigue response to sleep/rest were independent risk factors for depression, which merits attention for battling COVID-19.

Integrated System for On-Site Rapid and Safe Screening of COVID-19.

Since the outbreak of coronavirus disease 2019 (COVID-19), the epidemic has been spreading around the world for more than 2 years. Rapid, safe, and on-site detection methods of COVID-19 are in urgent demand for the control of the epidemic. Here, we established an integrated system, which incorporates a machine-learning-based Fourier transform infrared spectroscopy technique for rapid COVID-19 screening and air-plasma-based disinfection modules to prevent potential secondary infections. A partial least-squares discrimination analysis and a convolutional neural network model were built using the collected infrared spectral dataset containing 857 training serum samples. Furthermore, the sensitivity, specificity, and prediction accuracy could all reach over 94% from the results of the field test regarding 968 blind testing samples. Additionally, the disinfection modules achieved an inactivation efficiency of 99.9% for surface and airborne tested bacteria. The proposed system is conducive and promising for point-of-care and on-site COVID-19 screening in the mass population.

Impact of inactivated SARS-CoV-2 vaccination on embryo ploidy: a retrospective cohort study of 133 PGT-A cycles in China.

BACKGROUND: Unsubstantiated concerns have been raised on the potential correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infertility, leading to vaccine hesitancy in reproductive-aged population. Herein, we aim to evaluate the impact of inactivated SARS-CoV-2 vaccination on embryo ploidy, which is a critical indicator for embryo quality and pregnancy chance. METHODS: This was a retrospective cohort study of 133 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) cycles with next-generation sequencing technology from June 1st 2021 to March 17th 2022 at a tertiary-care medical center in China. Women fully vaccinated with two doses of Sinopharm or Sinovac inactivated vaccines (n = 66) were compared with unvaccinated women (n = 67). The primary outcome was the euploidy rate per cycle. Multivariate linear and logistic regression analyses were performed to adjust for potential confounders. RESULTS: The euploidy rate was similar between vaccinated and unvaccinated groups (23.2 ± 24.6% vs. 22.6 ± 25.9%, P = 0.768), with an adjusted ß of 0.01 (95% confidence interval [CI]: -0.08-0.10). After frozen-thawed single euploid blastocyst transfer, the two groups were also comparable in clinical pregnancy rate (75.0% vs. 60.0%, P = 0.289), with an adjusted odds ratio of 6.21 (95% CI: 0.76-50.88). No significant associations were observed between vaccination and cycle characteristics or other laboratory and pregnancy outcomes. CONCLUSIONS: Inactivated SARS-CoV-2 vaccination had no detrimental impact on embryo ploidy during in vitro fertilization treatment. Our finding provides further reassurance for vaccinated women who are planning to conceive. Future prospective cohort studies with larger datasets and longer follow-up are needed to confirm the conclusion.

Modelling international sovereign risk information spillovers: A multilayer network approach

Applying the TVP-VAR model, we creatively construct multilayer information spillover networks containing return spillover layer, volatility spillover layer and extreme risk spillover layer among 23 countries in the G20 to explore international sovereign risk spillovers. From the perspective of system-level and country-level measures, this article explores the topological structures of static and dynamic multilayer networks. We observe that (i) at the system-level, multilayer measures containing uniqueness edge ratio and average edge overlap show each layer has unique network structures and spillover evolution behavior, especially for dynamic networks. Average connectedness strength shows volatility and extreme risk spillover layers are more sensitive to extreme events. Meanwhile, three layers have highly intertwined and interrelated relations. Notably, their spillovers all show a great upsurge during the crisis (financial and European debt crisis) and the COVID-19 pandemic period. (ii) At the country-level, average overlapping net-strength shows that countries’ roles are different during distinct periods. Multiplex participation coefficient on out-strength indicates we’ll focus on countries with highly heterogeneous connectedness among three layers during the stable period since their underestimated spillovers soar in extreme events or crises. Multilayer networks supply comprehensive information that cannot obtain by single-layer.

An adjusted ELISpot-based immunoassay for evaluation of SARS-CoV-2-specific T-cell responses.

Like antibody evaluation, using an effective antigen-specific T-cell immunity assessment method in coronavirus disease 2019 (COVID-19) patients, survivors and vaccinees is crucial for understanding the immune persistence, prognosis assessment, and vaccine development for COVID-19. This study evaluated an empirically adjusted enzyme-linked immunospot assay for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T-cell immunity in 175 peripheral blood samples from COVID-19 convalescents and healthy individuals. Results of viral nucleic acid were used as the gold standard of infection confirmation. The SARS-CoV-2M peptide pool had higher sensitivity of 85% and specificity of 71% for the single peptide pool. For combined peptide pools, the parallel evaluation (at least one of the peptide pools is positive) of total peptide pools (S1&S2&M&N) had higher sensitivity (up to 93%), and the serial evaluation (all peptide pools are positive) of total peptide pools had higher specificity (up to 100%). The result of the serial evaluation was better than that of the parallel evaluation as a whole. The detection efficiency of M and N peptide pool serial evaluation appeared the highest, with a sensitivity of 80% and specificity of 93%. This T-cell immunity detection assay introduced in this report can achieve high operability and applicability. Therefore, it can be an effective SARS-CoV-2-specific cellular immune function evaluation method.

One-Year Sustained Cellular and Humoral Immunities in Coronavirus Disease 2019 (COVID-19) Convalescents.

BACKGROUND: The longitudinal antigen-specific immunity in COVID-19 convalescents is crucial for long-term protection upon individual re-exposure to SARS-CoV-2, and even more pivotal for ultimately achieving population-level immunity. We conducted this cohort study to better understand the features of immune memory in individuals with different disease severities at 1 year post-disease onset. METHODS: We conducted a systematic antigen-specific immune evaluation in 101 COVID-19 convalescents, who had asymptomatic, mild, moderate, or severe disease, through 2 visits at months 6 and 12 after disease onset. The SARS-CoV-2-specific antibodies, comprising neutralizing antibody (NAb), immunoglobulin (Ig) G, and IgM, were assessed by mutually corroborated assays (ie, neutralization, enzyme-linked immunosorbent assay [ELISA], and microparticle chemiluminescence immunoassay [MCLIA]). Meanwhile, T-cell memory against SARS-CoV-2 spike, membrane, and nucleocapsid proteins was tested through enzyme-linked immunospot assay (ELISpot), intracellular cytokine staining, and tetramer staining-based flow cytometry, respectively. RESULTS: SARS-CoV-2-specific IgG antibodies, and NAb, can persist among >95% of COVID-19 convalescents from 6 to 12 months after disease onset. At least 19/71 (26%) of COVID-19 convalescents (double positive in ELISA and MCLIA) had detectable circulating IgM antibody against SARS-CoV-2 at 12 months post-disease onset. Notably, numbers of convalescents with positive SARS-CoV-2-specific T-cell responses (≥1 of the SARS-CoV-2 antigen S1, S2, M, and N proteins) were 71/76 (93%) and 67/73 (92%) at 6 and 12 months, respectively. Furthermore, both antibody and T-cell memory levels in the convalescents were positively associated with disease severity. CONCLUSIONS: SARS-CoV-2-specific cellular and humoral immunities are durable at least until 1 year after disease onset.

An engineered bispecific human monoclonal antibody against SARS-CoV-2.

The global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires effective therapies against coronavirus disease 2019 (COVID-19), and neutralizing antibodies are a promising therapy. A noncompeting pair of human neutralizing antibodies (B38 and H4) blocking SARS-CoV-2 binding to its receptor, ACE2, have been described previously. Here, we develop bsAb15, a bispecific monoclonal antibody (bsAb) based on B38 and H4. bsAb15 has greater neutralizing efficiency than these parental antibodies, results in less selective pressure and retains neutralizing ability to most SARS-CoV-2 variants of concern (with more potent neutralizing activity against the Delta variant). We also selected for escape mutants of the two parental mAbs, a mAb cocktail and bsAb15, demonstrating that bsAb15 can efficiently neutralize all single-mAb escape mutants. Furthermore, prophylactic and therapeutic application of bsAb15 reduced the viral titer in infected nonhuman primates and human ACE2 transgenic mice. Therefore, this bsAb is a feasible and effective strategy to treat and prevent severe COVID-19.

Structures of the Omicron spike trimer with ACE2 and an anti-Omicron antibody.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant has become the dominant infective strain. We report the structures of the Omicron spike trimer on its own and in complex with angiotensin-converting enzyme 2 (ACE2) or an anti-Omicron antibody. Most Omicron mutations are located on the surface of the spike protein and change binding epitopes to many current antibodies. In the ACE2-binding site, compensating mutations strengthen receptor binding domain (RBD) binding to ACE2. Both the RBD and the apo form of the Omicron spike trimer are thermodynamically unstable. An unusual RBD-RBD interaction in the ACE2-spike complex supports the open conformation and further reinforces ACE2 binding to the spike trimer. A broad-spectrum therapeutic antibody, JMB2002, which has completed a phase 1 clinical trial, maintains neutralizing activity against Omicron. JMB2002 binds to RBD differently from other characterized antibodies and inhibits ACE2 binding.

Landscapes and dynamic diversifications of B-cell receptor repertoires in COVID-19 patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the pandemic of coronavirus disease 2019 (COVID-19). Great international efforts have been put into the development of prophylactic vaccines and neutralizing antibodies. However, the knowledge about the B cell immune response induced by the SARS-CoV-2 virus is still limited. Here, we report a comprehensive characterization of the dynamics of immunoglobin heavy chain (IGH) repertoire in COVID-19 patients. By using next-generation sequencing technology, we examined the temporal changes in the landscape of the patient's immunological status and found dramatic changes in the IGH within the patient's immune system after the onset of COVID-19 symptoms. Although different patients have distinct immune responses to SARS-CoV-2 infection, by employing clonotype overlap, lineage expansion, and clonotype network analyses, we observed a higher clonotype overlap and substantial lineage expansion of B cell clones 2-3 weeks after the onset of illness, which is of great importance to B-cell immune responses. Meanwhile, for preferences of V gene usage during SARS-CoV-2 infection, IGHV3-74 and IGHV4-34, and IGHV4-39 in COVID-19 patients were more abundant than those of healthy controls. Overall, we present an immunological resource for SARS-CoV-2 that could promote both therapeutic development as well as mechanistic research.