pH-Sensitive and Biodegradable Mn3(PO4)2·3H2O Nanoparticles as an Adjuvant of Protein-Based Bivalent COVID-19 Vaccine to Induce Potent and Broad-Spectrum Immunity.

Developing a novel and potent adjuvant with great biocompatibility for immune response augmentation is of great significance to enhance vaccine efficacy. In this work, we prepared a long-term stable, pH-sensitive, and biodegradable Mn3(PO4)2·3H2O nanoparticle (nano-MnP) by simply mixing MnCl2/NaH2PO4/Na2HPO4 solution for the first time and employed it as an immune stimulant in the bivalent COVID-19 protein vaccine comprised of wild-type S1 (S1-WT) and Omicron S1 (S1-Omicron) proteins as antigens to elicit a broad-spectrum immunity. The biological experiments indicated that the nano-MnP could effectively activate antigen-presenting cells through the cGAS-STING pathway. Compared with the conventional Alum-adjuvanted group, the nano-MnP-adjuvanted bivalent vaccine elicited approximately 7- and 8-fold increases in IgG antibody titers and antigen-specific IFN-γ secreting T cells, respectively. Importantly, antisera of the nano-MnP-adjuvanted group could effectively cross-neutralize the SARS-CoV-2 and its five variants of concern (VOCs) including Alpha, Beta, Gamma, Delta, and Omicron, demonstrating that this bivalent vaccine based on S1-WT and S1-Omicron proteins is an effective vaccine design strategy to induce broad-spectrum immune responses. Collectively, this nano-MnP material may provide a novel and efficient adjuvant platform for various prophylactic and therapeutic vaccines and provide insights for the development of the next-generation manganese adjuvant.

Comparison of chest CT features between progressive and nonprogressive patients with COVID-19 pneumonia: A meta-analysis.

OBJECTIVE: The aim of this study was to compare the radiographic features of patients with progressive and nonprogressive coronavirus disease 2019 (COVID-19) pneumonia. METHODS: PubMed, Embase, and Cochrane Library databases were searched from January 1, 2020, to February 28, 2022, by using the keywords: "COVID-19", "novel Coronavirus", "2019-novel coronavirus", "CT", "radiology" and "imaging". We summarized the computed tomography manifestations of progressive and nonprogressive COVID-19 pneumonia. The meta-analysis was performed using the Stata statistical software version 16.0. RESULTS: A total of 10 studies with 1092 patients were included in this analysis. The findings of this meta-analysis indicated that the dominating computed tomography characteristics of progressive patients were a crazy-paving pattern (odds ratio [OR] = 2.10) and patchy shadowing (OR = 1.64). The dominating lesions distribution of progressive patients were bilateral (OR = 11.62), central mixed subpleural (OR = 1.37), and central (OR = 1.36). The other dominating lesions of progressive patients were pleura thickening (OR = 2.13), lymphadenopathy (OR = 1.74), vascular enlargement (OR = 1.39), air bronchogram (OR = 1.29), and pleural effusion (OR = 1.29). Two patterns of lesions showed significant links with the progression of disease: nodule (P = .001) and crazy-paving pattern (P = .023). Four lesions distribution showed significant links with the progression of disease: bilateral (P = .004), right upper lobe (P = .003), right middle lobe (P = .001), and left upper lobe (P = .018). CONCLUSION: Nodules, crazy-paving pattern, and/or new lesions in bilateral, upper and middle lobe of right lung, and lower lobe of left lung may indicate disease deterioration. Clinicians should formulate or modify treatment strategies in time according to these specific conditions.

How Health-Related Misinformation Spreads Across the Internet: Evidence for the "Typhoon Eye" Effect.

Online health-related misinformation has become a major problem in society and in-depth research is needed to understand its propagation patterns and underlying mechanisms. This study proposes a psychological typhoon eye effect to understand how health-related misinformation spreads during the pandemic using two national studies. In Study 1, we collected online search data from the United States and China to explore the relationship between the physical distance from the epicenter and the spread of health-related misinformation. Two common pieces of health-related misinformation were examined: "Microwaves kill coronavirus" in the United States and "Taking a hot bath can prevent against COVID-19" in China. Our results indicated a "typhoon eye effect" in the spread of two actual pieces of health-related misinformation using online data from the United States and China. In Study 2, we fabricated a piece of health-related misinformation, "Wash Clothes with Salt Water to Block Infection," and measured the spread behavior and perceived credibility of the misinformation. Again, we observed a typhoon eye effect on the spread behavior as well as the perceived credibility of health-related misinformation among people with limited education. In addition, based on the stimulus-organism-response theory, perceived credibility could serve as a mediator in the relationship between physical distance from the epicenter and the spread of health-related misinformation. Our results highlight the importance of psychological approaches to understanding the propagation patterns of health-related misinformation. The present findings provide a new perspective for development of prevention and control strategies to reduce the spread of health-related misinformation during pandemics.

New-onset COVID-19-related diabetes: an early indicator of multi-organ injury and mortally of SARS-CoV-2 infection.

Objective: The pandemic of 2019 coronavirus (SARS-CoV-2) disease (COVID-19) has imposed a severe public health burden worldwide. Most patients with COVID-19 were mild. Severe patients progressed rapidly to critical condition including acute respiratory distress syndrome (ARDS), multi-organ failure and even death. This study aims to find early multi-organ injury indicators and blood glucose for predicting mortality of COVID-19. Methods: Fasting blood glucose (FBG) ≥7.0 mmol/L for two times during hospitalization and without a history of diabetes were defined as new-onset COVID-19-related diabetes (CRD). Indicators of injuries for multiple organs, including the lung, heart, kidney and liver, and glucose homeostasis were specifically analyzed for predicting death. Results: A total of 120 patients with a severity equal to or greater than Moderate were hospitalized. After excluding patients with history of diabetes, chronic heart, kidney, and liver disease, 69 patients were included in the final analysis. Of the 69 patients, 23 were Moderate, 20 were Severe, and 26 were Critical (including 16 deceased patients). Univariable analysis indicated that CRD, lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), creatine kinase (CK) and creatinine (Cr) were associated with death. Multivariable analysis indicated that CRD was an independent predictor for death (HR = 3.75, 95% CI 1.26-11.15). Abnormal glucose homeostasis or CRD occurred earlier than other indicators for predicting poor outcomes. Indicators of multiple organ injury were in parallel with the expression patterns of ACE2 (the SARS-CoV-2 receptor) in different organs including pancreatic islet. Conclusions: New-onset COVID-19-related diabetes is an early indicator of multi-organ injury and predictor for poor outcomes and death in COVID-19 patients. As it is easy to perform for clinical practices and self-monitoring, glucose testing will be helpful for predicting poor outcomes to facilitate appropriate intensive care.

Novel cleavage sites identified in SARS-CoV-2 spike protein reveal mechanism for cathepsin L-facilitated viral infection and treatment strategies.

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important target for vaccine and drug development. However, the rapid emergence of variant strains with mutated S proteins has rendered many treatments ineffective. Cleavage of the S protein by host proteases is essential for viral infection. Here, we discovered that the S protein contains two previously unidentified Cathepsin L (CTSL) cleavage sites (CS-1 and CS-2). Both sites are highly conserved among all known SARS-CoV-2 variants. Our structural studies revealed that CTSL cleavage promoted S to adopt receptor-binding domain (RBD) "up" activated conformations, facilitating receptor-binding and membrane fusion. We confirmed that CTSL cleavage is essential during infection of all emerged SARS-CoV-2 variants (including the recently emerged Omicron variant) by pseudovirus (PsV) infection experiment. Furthermore, we found CTSL-specific inhibitors not only blocked infection of PsV/live virus in cells but also reduced live virus infection of ex vivo lung tissues of both human donors and human ACE2-transgenic mice. Finally, we showed that two CTSL-specific inhibitors exhibited excellent In vivo effects to prevent live virus infection in human ACE2-transgenic mice. Our work demonstrated that inhibition of CTSL cleavage of SARS-CoV-2 S protein is a promising approach for the development of future mutation-resistant therapy.

Novel sites for Cathepsin L cleavage in SARS-CoV-2 spike guide treatment strategies (preprint)

The spike (S) protein of SARS coronavirus 2 (SARS-CoV-2) is an ideal target for the development of specific vaccines or drugs. However, treatments targeting viruses with mutant S proteins that have recently emerged in many countries are limited. Cleavage of the S protein by host proteases is essential for viral infection. Here, we discovered two novel sites (CS-1 and CS-2) in the S protein for cleavage by the protease Cathepsin L (CTSL). Both sites are highly conserved among all SARS-CoV-2 variants of concern. Cryo-electron microscopy structural studies revealed that CTSL cleavage increases the dynamics of the receptor binding domain of S and induces novel conformations. In our pseudovirus (PsV) infection experiment, alteration of the cleavage site significantly reduced the infection efficiency, and CTSL inhibitors markedly inhibited infection with PsVs of both the wild-type and emerged SARS-CoV-2 variants. Furthermore, six highly efficient CTSL inhibitors were found to effectively inhibit live virus infection in human cells in vitro , and two of these were further confirmed to prevent live virus infection in human ACE2 transgenic mice in vivo . Our work suggested that the CTSL cleavage sites in SARS-CoV-2 S are emerging new but effective targets for the development of mutation-resistant vaccines and drugs.

Mortality risk of COVID-19 in elderly males with comorbidities: a multi-country study.

The COVID-19 pandemic causes severe morbidity and mortality. This multi-country study aimed to explore risk factors that drive mortality in COVID-19 patients who received neither dexamethasone nor remdesivir. We analyzed a cohort of 568 survivors and 507 non-survivors from China, European regions, and North America. Elderly males ≥70 years accounted for only 25% of survivors, but this rate was significantly higher in non-survivors from China (55%), European regions (63%), and North America (47%). Compared with survivors, non-survivors had more incidences of comorbidities such as cerebrovascular disease and chronic obstructive pulmonary disease (COPD, p-values<0.05). Survival analyses revealed age, male gender, shortness of breath, cerebrovascular disease, and COPD as mortality-associated factors. Survival time from symptom onset was significantly shorter in elderly versus young patients (median: 29 versus 62 days), males versus females (median: 46 versus 59 days), and patients with versus without comorbidities (mean: 41 versus 61 days). Mortality risk was higher in elderly males with comorbidities than in young females without comorbidities (p-value<0.01). Elderly male survivors with comorbidities also had longer hospital stays than other survivors (25 versus 18.5 days, p-value<0.01). Overall, the high mortality risk in elderly males with COVID-19-associated comorbidities supports early prevention and critical care for elderly populations.

Cathepsin L plays a key role in SARS-CoV-2 infection in humans and humanized mice and is a promising target for new drug development (preprint)

To discover new drugs to combat COVID-19, an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L (CTSL) in patients with COVID-19. The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity. Correspondingly, SARS-CoV-2 pseudovirus infection increased CTSL expression in human cells in vitro and human ACE2 transgenic mice in vivo, while CTSL overexpression, in turn, enhanced pseudovirus infection in human cells. CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry, as evidenced by CTSL overexpression and knockdown in vitro and application of CTSL inhibitor drugs in vivo. Furthermore, amantadine, a licensed anti-influenza drug, significantly inhibited CTSL activity after SARS-CoV-2 pseudovirus infection and prevented infection both in vitro and in vivo. Therefore, CTSL is a promising target for new anti-COVID-19 drug development.

Perceived Control Buffers the Effects of the COVID-19 Pandemic on General Health and Life Satisfaction: The Mediating Role of Psychological Distance.

BACKGROUND: Ways to maintain good health during a pandemic are very important for the general population; however, little is known about the impact of the coronavirus disease 2019 (COVID-19) on individuals' life satisfaction and perceived general health. This study aimed to examine the effects of COVID-19 on life satisfaction and perceived general health and reveal the buffering effect of perceived control on coping with COVID-19. METHODS: We collected 1,847 participants' data from 31 pandemic-affected provinces in China and obtained regional epidemic data of the same provinces. We employed a moderated mediation model with both individuals' self-report data and regional epidemic data to verify the hypotheses. RESULTS: Psychological distance mediated the relationships of regional pandemic severity with perceived general health and life satisfaction. Perceived control moderated the detrimental effects of regional pandemic severity through the moderating effects of regional pandemic severity on psychological distance, as well as the moderating effects of psychological distance on life satisfaction. CONCLUSIONS: Our findings indicate that perceived control may act as a protective factor buffering the psychological impact of the pandemic on general health and life satisfaction. Psychological distance can serve as a mediator that explains how the COVID-19 pandemic impacts perceived general health and life satisfaction.

Analysis on the layout of China’s emergency research projects during the public health emergency of COVID-19 / 中华医学科研管理杂志

Objective@#To explore the main layout and countermeasures of Scientific research projects during the public health emergency of COVID-19.@*Methods@#Literature investigation method is applied to collect information of scientific research and emergency research projects of COVID-19 funded since January 20th by different entities including national, provincial and municipal administrative departments, public health agencies, research institutes, universities and industries.@*Results@#Along with priorities identified for the emergency response and key research agendas, the national science and technology authorities at all levels and scientific research institutions have deployed a series of new science and technology projects, as well as a number of supporting policies and measures.@*Conclusions@#In the campaign of science and technology to deal with COVID-19, the leadership of Chinese government and their coordination with local agencies facilitated quick response in both R&D investment and supporting policies. Periodical achievement is recognized so far, and with the continuous development and in-depth research, the related scientific research results will be gathered into the core force of epidemic prevention. Moreover, it will improve China's capacity to deal with health emergencies and the level of medical health innovation, and better protect the health of the people.