Effects of Porcine deltacoronavirus on the transduction pathway of the innate immune signal

Porcine deltacoronavirus (PDCOV) is a new type of pig intestinal coronavirus, which targets pig small intestinal epithelial cells to cause severe enteritis. After infecting the host, PDCoV finishes its proliferation in the host cell by antagonism or escape the innate immune signaling transduction pathway. In order to understand the action mechanism of PDCOV 0n the congenital immune signal transduction pathways, this paper reviews the effects of PDCOV on RLR, Jak-STAT, MAPK and mitochondrial signaling pathway to clarify the relationship between PDCOV and host innate immune signaling transduction pathways in order to provide help for the prevention and treatment of PDCOV infection.

Ratiometric fluorescence immunoassay of SARS-CoV-2 nucleocapsid protein via Si-FITC nanoprobe-based inner filter effect.

The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has necessitated rapid, easy-to-use, and accurate diagnostic methods to monitor the virus infection. Herein, a ratiometric fluorescence enzyme-linked immunosorbent assay (ELISA) was developed using Si-fluorescein isothiocyanate nanoparticles (FITC NPs) for detecting SARS-CoV-2 nucleocapsid (N) protein. Si-FITC NPs were prepared by a one-pot hydrothermal method using 3-aminopropyl triethoxysilane (APTES)-FITC as the Si source. This method did not need post-modification and avoided the reduction in quantum yield and stability. The p-nitrophenyl (pNP) produced by the alkaline phosphatase (ALP)-mediated hydrolysis of p-nitrophenyl phosphate (pNPP) could quench Si fluorescence in Si-FITC NPs via the inner filter effect. In ELISA, an immunocomplex was formed by the recognition of capture antibody/N protein/reporter antibody. ALP-linked secondary antibody bound to the reporter antibody and induced pNPP hydrolysis to specifically quench Si fluorescence in Si-FITC NPs. The change in fluorescence intensity ratio could be used for detecting N protein, with a wide linearity range (0.01-10.0 and 50-300 ng/mL) and low detection limit (0.002 ng/mL). The concentration of spiked SARS-CoV-2 N protein could be determined accurately in human serum. Moreover, this proposed method can accurately distinguish coronavirus disease 2019 (COVID-19) and non-COVID-19 patient samples. Therefore, this simple, sensitive, and accurate method can be applied for the early diagnosis of SARS-CoV-2 virus infection. Electronic Supplementary Material: Supplementary material (characterization of Si-FITC NPs (FTIR spectrum, XRD spectra, and synchronous fluorescence spectra); condition optimization of ALP response (fluorescence intensity ratio change); mechanism investigation of ALP response (fluorescence lifetime decay curves and UV-vis absorption spectra); detection of N protein using commercial ELISA Kit; analytical performance of assays for ALP detection or SARS-CoV-2 N protein detection; and determination results of SARS-CoV-2 N protein in human serum) is available in the online version of this article at 10.1007/s12274-022-4740-5.

Restorative properties of green sheltered spaces and their morphological characteristics in urban parks

The properties of green space for physical and mental health have been widely demonstrated, especially after the COVID-19 pandemic. However, few studies have systematically focused on spatial indicator thresholds that provide a sense of refuge with restoration benefits. Four morphological indicators as area, coverage, enclosure, and the ratio of width to height(D/H), were quantified for thirty-one scenes in outdoor green sheltered spaces in seven urban parks of Harbin in China. The results show that the sense of refuge and the morphological character of a green space constitute elements that influence restorative properties. Green spaces with different morphological indicators have different restorative properties. The morphological indicator ranges that produce better restorative properties were obtained: 250 m2 to 500 m2 for area, 0.25-0.35 for coverage, 0.3-0.4 or 0.8-1 for enclosure, and 0.7-1.5 for D/H. This can provide references for the construction of restorative activity spaces in urban parks.

McAN: a novel computational algorithm and platform for constructing and visualizing haplotype networks.

Haplotype networks are graphs used to represent evolutionary relationships between a set of taxa and are characterized by intuitiveness in analyzing genealogical relationships of closely related genomes. We here propose a novel algorithm termed McAN that considers mutation spectrum history (mutations in ancestry haplotype should be contained in descendant haplotype), node size (corresponding to sample count for a given node) and sampling time when constructing haplotype network. We show that McAN is two orders of magnitude faster than state-of-the-art algorithms without losing accuracy, making it suitable for analysis of a large number of sequences. Based on our algorithm, we developed an online web server and offline tool for haplotype network construction, community lineage determination, and interactive network visualization. We demonstrate that McAN is highly suitable for analyzing and visualizing massive genomic data and is helpful to enhance the understanding of genome evolution. Availability: Source code is written in C/C++ and available at https://github.com/Theory-Lun/McAN and https://ngdc.cncb.ac.cn/biocode/tools/BT007301 under the MIT license. Web server is available at https://ngdc.cncb.ac.cn/bit/hapnet/. SARS-CoV-2 dataset are available at https://ngdc.cncb.ac.cn/ncov/. Contact: songshh@big.ac.cn (Song S), zhaowm@big.ac.cn (Zhao W), baoym@big.ac.cn (Bao Y), zhangzhang@big.ac.cn (Zhang Z), ybxue@big.ac.cn (Xue Y).

N-Butanol Extract of Glycyrrhizae Radix et Rhizoma Inhibits Dengue Virus through Targeting Envelope Protein.

BACKGROUND: At present, about half of the world's population is at risk of being infected with dengue virus (DENV). However, there are no specific drugs to prevent or treat DENV infection. Glycyrrhizae Radix et Rhizome, a well-known traditional Chinese medicine, performs multiple pharmacological activities, including exerting antiviral effects. The aim of this study was to investigate the anti-DENV effects of n-butanol extract from Glycyrrhizae Radix et Rhizome (GRE). METHODS: Compounds analysis of GRE was conducted via ultra-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). The antiviral activities of GRE were determined by the CCK-8 assay, plaque assay, qRT-PCR, Western blotting, and the immunofluorescence assay. The DENV-infected suckling mice model was constructed to explore the antiviral effects of GRE in vivo. RESULTS: Four components in GRE were analyzed by UHPLC-MS/MS, including glycyrrhizic acid, glycyrrhetnic acid, liquiritigenin, and isoliquiritigenin. GRE inhibited the attachment process of the virus replication cycle and reduced the expression of the E protein in cell models. In the in vivo study, GRE significantly relieved clinical symptoms and prolong survival duration. GRE also significantly decreased viremia, reduced the viral load in multiple organs, and inhibited the release of pro-inflammatory cytokines in DENV-infected suckling mice. CONCLUSIONS: GRE exhibited significant inhibitory activities in the adsorption stage of the DENV-2 replication cycle by targeting the envelope protein. Thus, GRE might be a promising candidate for the treatment of DENV infection.

Specific pupylation as IDEntity reporter (SPIDER) for the identification of protein-biomolecule interactions.

Protein-biomolecule interactions play pivotal roles in almost all biological processes. For a biomolecule of interest, the identification of the interacting protein(s) is essential. For this need, although many assays are available, highly robust and reliable methods are always desired. By combining a substrate-based proximity labeling activity from the pupylation pathway of Mycobacterium tuberculosis and the streptavidin (SA)-biotin system, we developed the Specific Pupylation as IDEntity Reporter (SPIDER) method for identifying protein-biomolecule interactions. Using SPIDER, we validated the interactions between the known binding proteins of protein, DNA, RNA, and small molecule. We successfully applied SPIDER to construct the global protein interactome for m6A and mRNA, identified a variety of uncharacterized m6A binding proteins, and validated SRSF7 as a potential m6A reader. We globally identified the binding proteins for lenalidomide and CobB. Moreover, we identified SARS-CoV-2-specific receptors on the cell membrane. Overall, SPIDER is powerful and highly accessible for the study of protein-biomolecule interactions.

China's auto industry: regimes of production and industrial policy in the age of electric cars

This article discusses China's industrial and labour policy for the automotive industry facing the transition to the era of new energy vehicles. A conceptual framework on the regimes of production is employed to analyse the present transformation of industry structures in production models and labour markets. The growth of private-capitalist regimes of high-performance, low wages, and high profit incentives for workers is identified, which can be described as the 'Foxconnisation' of the industry, and it is at the expense of the corporate-bureaucratic regimes prevalent among the leading Sino-foreign joint ventures. As production networks become vertically disintegrated, some non-traditional industrial players are highlighted in the discussion of some recent developments in the industry during the ongoing COVID-19 pandemic. The profound transformation in the regimes of production brought about social contradictions related to the production process, and new challenges and implications for workplace policies. The empirical study of this article confirms the necessity of trade union strategies inside China from an international perspective in order to ensure social standards and a more sustainable green transformation of the industry.

A simple and effective aerosol pathogen disinfection test for a flowing air disinfector

Aerosol transmission is an important disease transmission route and has been especially pertinent to hospital and biosafety laboratories during the SARS-CoV-2 pandemic. The thermal resistance of airborne SARS-CoV-2 is lower than that of Bacillus subtilis spores, which are often used to test the effectiveness of SARS-CoV-2 and other pathogen disinfection methods. Herein, we propose a new method to test the disinfection ability of a flowing air disinfector (a digital electromagnetic induction air heater) using B. subtilis spores. The study provides an alternative air disinfection test method. The new test system combined an aerosol generator and a respiratory filter designed in-house and could effectively recover spores on the filter membrane at the air outlet after passing through the flowing air disinfector. The total number of bacterial spores used in the test was within the range of 5 × 105–5 × 106 colony-forming units (CFUs) specified in the technical standard for disinfection. The calculation was based on the calculation method in Air Disinfection Effect Appraisal Test in Technical Standard for Disinfection (2002 Edition). At an air speed of 3.5 m/s, we used a digital electromagnetic induction air heater to disinfect flowing air containing 4.100 × 106 CFUs of B. subtilis spores and determined that the minimum disinfection temperature was 350 °C for a killing rate of 99.99%. At 400 °C, additional experiments using higher spore concentrations (4.700 × 106 ± 1.871 × 105 CFU) and a higher airspeed (4 m/s) showed that the killing rate remained>99.99%. B. subtilis spores, as a biological indicator for testing the efficiency of dry-heat sterilization, were killed by the high temperatures used in this system. The proposed method used to test the flowing air disinfector is simple, stable, and effective. This study provides a reference for the development of test systems that can assess the disinfection ability of flowing air disinfectors.

Self-affirmation increases acceptance of information on COVID-19 vaccines and promotes vaccination intention.

Previous studies have shown that self-affirmation increases acceptance of a message and motivates health behavior change. The present study investigated whether self-affirmation increases the acceptance of persuasive messages on COVID-19 vaccines and promotes vaccination intention. A total of 144 participants were randomly assigned to the self-affirmation (n = 72) or control (n = 72) groups before reading a persuasive message on COVID-19 vaccines. The results revealed that the self-affirmation group showed significantly higher acceptance of persuasive information on COVID-19 vaccines than the control group. Additionally, the self-affirmation group also showed significantly higher post-experiment vaccination intention than the control group. Mediation analysis indicated that increased acceptance of persuasive information significantly mediated the beneficial effects of self-affirmation on post-experiment vaccination intention. The present study demonstrated that self-affirmation could be an effective strategy for increasing the acceptance of persuasive messages on COVID-19 vaccines and promoting vaccination intention.

Refocus on Immunogenic Characteristics of Convalescent COVID-19 Challenged by Prototype SARS-CoV-2.

Background: Mass basic and booster immunization programs effectively contained the spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, also known as COVID-19. However, the emerging Variants of Concern (VOCs) of COVID-19 evade the immune protection of the vaccine and increase the risk of reinfection. Methods: Serum antibodies of 384 COVID-19 cases recovered from SARS-CoV-2 infection were examined. Correlations between clinical symptoms and antibodies against VOCs were analyzed. Result: All 384 cases (aged 43, range 1−90) were from 15 cities of Guangdong, China. The specific IgA, IgG, and IgM antibodies could be detected within 4−6 weeks after infection. A broad cross-reaction between SARS-CoV-2 and Severe Acute Respiratory Syndrome Coronavirus, but not with Middle East Respiratory Syndrome Coronavirus was found. The titers of neutralization antibodies (NAbs) were significantly correlated with IgG (r = 0.667, p < 0.001), but showed poor neutralizing effects against VOCs. Age, fever, and hormone therapy were independent risk factors for NAbs titers reduction against VOCs. Conclusion: Humoral immunity antibodies from the original strain of COVID-19 showed weak neutralization effects against VOCs, and decreased neutralizing ability was associated with initial age, fever, and hormone therapy, which hindered the effects of the COVID-19 vaccine developed from the SARS-CoV-2 prototype virus.

Clinical significance of serum IgM and IgG levels in COVID-19 patients in Hubei Province, China.

Background: There have been many studies about coronavirus disease 2019 (COVID-19), but the clinical significance of quantitative serum severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-specific IgM and IgG levels of COVID-19 patients have not been exhaustively analyzed. We aimed to investigate the time profiles of these IgM/IgG levels in COVID-19 patients and their correlations with clinical features. Methods: A multicenter clinical study was conducted from February 20 to March 5 2020. It involved 179 COVID-19 patients (108 males and 71 females) from five hospitals in Huangshi in Hubei Province, China. To detect SARS-CoV-2-specific IgM/IgG, quantitative antibody assays (two-step indirect immunoassays with direct chemiluminescence technology) based on the nucleocapsid protein (NP) and spike protein 1 (S1) were used. For normally distributed data, means were compared using the t-test, χ 2-test, or exact probability method. For categorical data, medians were compared using Mann-Whitney U test. Results: The median age was 57 (44-69) years (58 [38-69] for males and 57 [49-68] for females). The median duration of positive nucleic acid test was 22.32 (17.34-27.43) days. The mortality rate was relatively low (3/179, 1.68%). Serum SARS-CoV-2-specific IgG was detected around week 1 after illness onset, gradually increased until peaking in weeks 4 and 5, and then declined. Serum IgM peaked in weeks 2 and 3, then gradually declined and returned to its normal range by week 7 in all patients. Notably, children had milder respiratory symptoms with lower SARS-CoV-2-specific IgM/IgG levels. The duration of positive nucleic acid test in the chronic obstructive pulmonary disease (COPD) group was 30.36 (18.99-34.76) days, which was significantly longer than that in the non-COPD group (21.52 [16.75-26.51] days; P = 0.025). The peak serum SARS-CoV-2-specific IgG was significantly positively correlated with the duration of positive nucleic acid test. The incidence rate of severe and critical cases in the IgMhi group (using the median IgM level of 29.95 AU/mL as the cutoff for grouping) was about 38.0% (19/50), which was twice as much as that in the IgMlo group (18.4%; 9/49). The patients with positive chest imaging and lymphocytopenia (<1 × 109/L) had a higher SARS-CoV-2-specific IgM level. Conclusions: Quantitative SARS-CoV-2-specific IgM and IgG levels are helpful for the diagnosis, severity classification, and management of COVID-19 patients, and they should be monitored in each stage of this disease.

Two-year follow-up of brain structural changes in patients who recovered from COVID-19: A prospective study.

The long-term effects of COVID-19 on brain structure remain unclear. A prospective study was conducted to explore the changes in brain structure in COVID-19 survivors at one and two years after discharge (COVID-19one, COVID-19two). The difference in gray matter volume (GMV) was analyzed using the voxel-based morphometry method, and correlation analyses were conducted. The dynamic changes in clinical sequelae varied. The GMVs in the cerebellum and vermis were reduced in COVID-19one and COVID-19two, positively correlated with lymphocyte count, and negatively correlated with neutrophil count, neutrophil/lymphocyte ratio (COVID-19one), and systemic immune-inflammation index (COVID-19two). The decreased GMVs in the left middle frontal gyrus, inferior frontal gyrus of the operculum, right middle temporal gyrus, and inferior temporal gyrus returned to normal in COVID-19two. The decreased GMV in the left frontal lobe was negatively correlated with the Athens Insomnia Scale (AIS). The GMV in the left temporal lobe was aggravated in COVID-19two and positively correlated with C-reactive protein. In conclusion, GMV recovery coexisted with injury, which was associated with AIS and inflammatory factors. This may shed some light on the dynamic changes in brain structure and the possible predictors that may be related to GMV changes in COVID-19two.

Recent developments in the immunopathology of COVID-19.

There has been an important change in the clinical characteristics and immune profile of Coronavirus disease 2019 (COVID-19) patients during the pandemic thanks to the extensive vaccination programs. Here, we highlight recent studies on COVID-19, from the clinical and immunological characteristics to the protective and risk factors for severity and mortality of COVID-19. The efficacy of the COVID-19 vaccines and potential allergic reactions after administration are also discussed. The occurrence of new variants of concerns such as Omicron BA.2, BA.4, and BA.5 and the global administration of COVID-19 vaccines have changed the clinical scenario of COVID-19. Multisystem inflammatory syndrome in children (MIS-C) may cause severe and heterogeneous disease but with a lower mortality rate. Perturbations in immunity of T cells, B cells, and mast cells, as well as autoantibodies and metabolic reprogramming may contribute to the long-term symptoms of COVID-19. There is conflicting evidence about whether atopic diseases, such as allergic asthma and rhinitis, are associated with a lower susceptibility and better outcomes of COVID-19. At the beginning of pandemic, the European Academy of Allergy and Clinical Immunology (EAACI) developed guidelines that provided timely information for the management of allergic diseases and preventive measures to reduce transmission in the allergic clinics. The global distribution of COVID-19 vaccines and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with reduced pathogenic potential dramatically decreased the morbidity, severity, and mortality of COVID-19. Nevertheless, breakthrough infection remains a challenge for disease control. Hypersensitivity reactions (HSR) to COVID-19 vaccines are low compared to other vaccines, and these were addressed in EAACI statements that provided indications for the management of allergic reactions, including anaphylaxis to COVID-19 vaccines. We have gained a depth knowledge and experience in the over 2 years since the start of the pandemic, and yet a full eradication of SARS-CoV-2 is not on the horizon. Novel strategies are warranted to prevent severe disease in high-risk groups, the development of MIS-C and long COVID-19.

Tracking of Mutational Signature of SARS-CoV-2 Omicron on Distinct Continents and Little Difference was Found.

The Omicron variant is currently ravaging the world, raising serious concern globally. Monitoring genomic variations and determining their influence on biological features are critical for tracing its ongoing transmission and facilitating effective measures. Based on large-scale sequences from different continents, this study found that: (i) The genetic diversity of Omicron is much lower than that of the Delta variant. Still, eight deletions (Del 1-8) and 1 insertion, as well as 130 SNPs, were detected on the Omicron genomes, with two deletions (Del 3 and 4) and 38 SNPs commonly detected on all continents and exhibiting high-occurring frequencies. (ii) Four groups of tightly linked SNPs (linkage I-IV) were detected, among which linkage I, containing 38 SNPs, with 6 located in the RBD, increased its occurring frequency remarkably over time. (iii) The third codons of the Omicron shouldered the most mutation pressures, while the second codons presented the least flexibility. (iv) Four major mutants with amino acid substitutions in the RBD were detected, and further structural analysis suggested that the substitutions did not alter the viral receptor binding ability greatly. It was inferred that though the Omicron genome harbored great changes in antigenicity and remarkable ability to evade immunity, it was immune-pressure selected. This study tracked mutational signatures of Omicron variant and the potential biological significance of the SNPs, and the linkages await further functional verification.

RT-RPA-Cas12a-based assay facilitates the discrimination of SARS-CoV-2 variants of concern.

Timely and accurate detection of SARS-CoV-2 variants of concern (VOCs) is urgently needed for pandemic surveillance and control. Great efforts have been made from a mass of scientists in increasing the detection sensitivity and operability, and reducing the turn-around time and cost. Here, we report a nucleic acid testing-based method aiming to detect and discriminate SARS-CoV-2 mutations by combining RT-RPA and CRISPR-Cas12a detecting assays (RRCd). With a detection limit of 10 copies RNA/reaction, RRCd was validated in 194 clinical samples, showing 89% positive predictive agreement and 100% negative predictive agreement, respectively. Critically, using specific crRNAs, representatives of single nucleotide polymorphisms and small deletions in SARS-CoV-2 VOCs including N501Y, T478K and ΔH69-V70 were discriminated by RRCd, demonstrating 100% specificity in clinical samples with C t < 33. The method completes within 65 min and could offer visible results without using any electrical devices, which probably facilitate point-of-care testing of SARS-CoV-2 variants and other epidemic viruses.

Adaptive immune responses and cytokine immune profiles in humans following prime and boost vaccination with the SARS-CoV-2 CoronaVac vaccine.

BACKGROUND: Adaptive immune response has been thought to play a key role in SARS-CoV-2 infection. The role of B cells, CD4+T, and CD8+T cells are different in vaccine-induced immune response, thus it is imperative to explore the functions and kinetics of adaptive immune response. We collected blood samples from unvaccinated and vaccinated individuals. To assess the mechanisms contributing to protective immunity of CoronaVac vaccines, we mapped the kinetics and durability of humoral and cellular immune responses after primary and boost vaccination with CoronaVac vaccine in different timepoints. MATERIALS AND METHODS: We separate PBMC and plasma from blood samples. The differentiation and function of RBD-spcific CD4+T and CD8+T cells were analyzed by flow cytometry and ELISA. Antibodies response was analyzed by ELISA. ELISPOT analysis was perfomed to detected the RBD-spcific memory B cells. CBA analysis was performed to detected the cytokine immune profiles. Graphpad prism 8 and Origin 2021 were used for statistical analysis. RESULTS: Vaccine-induced CD4+T cell responses to RBD were more prominent than CD8+T cell responses, and characterized by a predominant Th1 and weak Th17 helper response. CoronaVac vaccine triggered predominant IgG1 antibody response and effectively recalled specific antibodies to RBD protein after booster vaccination. Robust antigen-specific memory B cells were detected (p < 0.0001) following booster vaccination and maintained at 6 months (p < 0.0001) following primary vaccination. Vaccine-induced CD4+T cells correlated with CD8+T cells (r = 0.7147, 0.3258, p < 0.0001, p = 0.04), memory B cell responses (r = 0.7083, p < 0.0001), and IgG and IgA (r = 0.6168, 0.5519, p = 0.0006, 0.003) after vaccination. In addition, vaccine induced a broader and complex cytokine pattern in plasma at early stage. CONCLUSION: Taken together, these results highlight the potential role of B cell and T cell responses in vaccine-induced long-term immunity.

Influence of Anxiety and Depression on the Symptoms of Achalasia Patients: A Retrospective Cohort Study in China during COVID-19.

BACKGROUND: Idiopathic achalasia (AC) may be affected by anxiety and/or depression; however, reliable evidence is still lacking. The present retrospective cohort study aimed to explore the influence of psycho-mental factors on the severity of AC. METHODS: All patients in the AC database of the Tianjin Medical University General Hospital from 2012 to 2020 were divided into two subgroups, intervention (n = 202) and medication (n = 84), according to previous treatments. Healthy people (n = 300) who underwent gastrointestinal endoscopy comprised the control group. The severity of symptoms and the anxiety and depression score of AC patients and controls were monitored by telephone and compared before and during COVID-19. In addition, the factors of AC symptoms during the COVID-19 were discussed by multiple linear regression. RESULTS: During COVID-19, the anxiety and depression levels of AC patients and healthy individuals were deteriorated. For AC patients, before and after COVID-19, symptoms, anxiety, and depression scores in the medication group were more serious than those in the intervention group. Furthermore, previous therapy, depression, and gender were found to be significantly related to the severity of AC symptoms during COVID-19. CONCLUSIONS: The outbreak of COVID-19 made AC patients and healthy people anxious and depressed. Depression rather than anxiety might worsen the AC symptoms. Interventional therapy might protect AC patients against psychological abnormalities during COVID-19.

Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study.

Background and purpose: Long COVID with regard to the neurological system deserves more attention, as a surge of treated patients are being discharged from the hospital. As the dynamic changes in white matter after two years remain unknown, this characteristic was the focus of this study. Methods: We investigated 17 recovered COVID-19 patients at two years after discharge. Diffusion tensor imaging, neurite orientation dispersion and density imaging were performed to identify white matter integrity and changes from one to two years after discharge. Data for 13 revisited healthy controls were collected as a reference. Subscales of the Wechsler Intelligence scale were used to assess cognitive function. Repeated-measures ANOVA was used to detect longitudinal changes in 17 recovered COVID-19 patients and 13 healthy controls after one-year follow-up. Correlations between diffusion metrics, cognitive function, and other clinical characteristics (i.e., inflammatory factors) were also analyzed. Results: Longitudinal analysis showed the recovery trends of large-scale brain regions, with small-scale brain region deterioration from one year to two years after SARS-CoV-2 infection. However, persistent white matter abnormalities were noted at two years after discharge. Longitudinal changes of cognitive function showed no group difference. But cross-sectional cognitive difference between recovered COVID-19 patients and revisited HCs was detected. Inflammation levels in the acute stage correlated positively with white matter abnormalities and negatively with cognitive function. Moreover, the more abnormal the white matter was at two years, the greater was the cognitive deficit present. Conclusion: Recovered COVID-19 patients showed longitudinal recovery trends of white matter. But also had persistent white matter abnormalities at two years after discharge. Inflammation levels in the acute stage may be considered predictors of cognition and white matter integrity, and the white matter microstructure acts as a biomarker of cognitive function in recovered COVID-19 patients. These findings provide an objective basis for early clinical intervention.

Depression, anxiety, stress, and physical activity of Australian adults during COVID-19: A combined longitudinal and repeated cross-sectional study

Background The COVID-19 pandemic has led to a worsening of mental health and health behaviors. While physical activity is positively associated mental health, there is limited understanding of how mental health and physical activity evolve throughout the COVID-19 pandemic. This study aimed to examine changes in depression, anxiety and stress and physical activity, and associations between depression, anxiety, and stress with physical activity in Australian adults across three-time points during the COVID-19 pandemic. Materials and methods This study collected both longitudinal and cross-sectional data at three-time points during the COVID-19 pandemic in Australia (i.e., April, July/August, and December 2020). Australians aged 18 years and over were invited to complete online surveys hosted on Qualtrics survey platform. Linear mixed models with random subject effect and general linear models were used to analyze the longitudinal and repeated cross-sectional data respectively. Results The number of participants in cross-sectional surveys and longitudinal surveys was 1,877 and 849, respectively. There was an overall reduction between time 2 vs. time 3 in depression (d = 1.03, 95% CI = 0.20, 1.85), anxiety (d = 0.57, 95% CI = 0.02, 1.12), and stress (d = 1.13, 95% CI = 0.21, 2.04) scores but no significant differences in physical activity across three-time points. On average, participants who met the physical activity guidelines had lower depression (d = −2.08, 95% CI = −2.90, −1.26), anxiety (d = −0.88, 95% CI = −1.41, −0.34), and stress (d = −1.35, 95% CI = −2.13, −0.56) scores compared to those not meeting the guidelines. Conclusion In the context of the ongoing COVID-19 pandemic, both governments and service providers should continue to provide the public with timely mental health support and promote the benefits of physical activity, as a cost-effective strategy to improve mental health and wellbeing.

Immune Persistence against SARS-CoV-2 after Primary and Booster Immunization in Humans: A Large-Scale Prospective Cohort Study.

Amid the ongoing global COVID-19 pandemic, limited literature exists on immune persistence after primary immunization and the immunogenic features of booster vaccines administered at different time intervals. Therefore, this study aimed to determine the immune attenuation of neutralizing antibodies against the SARS-CoV-2 wild-type strain, and Delta and Omicron variants 12 months after the primary administration of the COVID-19 inactivated vaccine and evaluate the immune response after a booster administration at different time intervals. A total of 514 individuals were followed up after primary immunization and were vaccinated with a booster. Neutralizing antibodies against the wild-type strain and Delta and Omicron variant spike proteins were measured using pseudovirus neutralization assays. The geometric mean titers (GMTs) after the primary and booster immunizations were 12.09 and 61.48 for the wild-type strain, 11.67 and 40.33 for the Delta variant, and 8.51 and 29.31 for the Omicron variant, respectively. The GMTs against the wild-type strain declined gradually during the 12 months after the primary immunization, and were lower against the two variants. After implementing a booster immunization with a 6 month interval, the GMTs against the wild-type strain were higher than those obtained beyond the 7 month interval; however, the GMTs against the two variants were not statistically different across 3-12 month intervals. Overall, SARS-CoV-2 variants showed remarkable declines in immune persistence, especially against the Omicron variant. The booster administration interval could be shortened to 3 months in endemic areas of the Omicron variant, whereas an appropriate prolonging of the booster administration interval did not affect the booster immunization effect.