Convalescent Patients Research Articles

The alphavirus determinants of intercellular long extension formation.

The alphavirus chikungunya virus (CHIKV) is a serious human pathogen that can cause large-scale epidemics characterized by fever and joint pain and often resulting in chronic arthritis. Infection by alphaviruses including CHIKV and the closely related Semliki Forest virus (SFV) can induce the formation of filopodia-like intercellular long extensions (ILEs). ILEs emanate from an infected cell, stably attach to a neighboring cell, and mediate cell-to-cell viral transmission that is resistant to neutralizing antibodies. However, our mechanistic understanding of ILE formation is limited, and the potential contribution of ILEs to CHIKV virulence or human CHIKV infection is unknown. Here, we used well-characterized virus mutants and monoclonal antibodies with known epitopes to dissect the virus requirements for ILE formation. Our results showed that both the viral E2 and E1 envelope proteins were required for ILE formation, while viral proteins 6K and transframe, and cytoplasmic nucleocapsid formation were dispensable. A subset of CHIKV monoclonal antibodies reduced ILE formation by masking specific regions particularly on the E2 A domain. Studies of the viral proteins from different CHIKV strains showed that ILE formation is conserved across the four major CHIKV lineages. Sera from convalescent human CHIKV patients inhibited ILE formation in cell culture, providing the first evidence for ILE inhibitory antibody production during human CHIKV infections.IMPORTANCEChikungunya virus (CHIKV) infections can cause severe fever and long-lasting joint pain in humans. CHIKV is disseminated by mosquitoes and is now found world-wide, including in the Americas, Asia, and Africa. In cultured cells, CHIKV can induce the formation of long intercellular extensions that can transmit virus to another cell. However, our understanding of the formation of extensions and their importance in human CHIKV infection is limited. We here identified viral protein requirements for extension formation. We demonstrated that specific monoclonal antibodies against the virus envelope proteins or sera from human CHIKV patients can inhibit extension formation. Our data highlight the importance of evaluation of extension formation in the context of human CHIKV infection.

The effect of pressing needle therapy on depression, anxiety, and sleep for patients in convalescence from COVID-19

ObjectiveTo evaluate the effect of pressing needle therapy on depression, anxiety, and sleep in patients recovering from COVID-19, and to provide a more effective and convenient treatment for the sequelae of COVID-19.MethodsA total of 136 patients recovering from COVID-19 were randomized into a treatment group (68 cases) and a control group (68 cases, with one case dropping out). The treatment group received pressing needle therapy, while the control group received sham pressing needle therapy, three times a week for 4 weeks. The Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder Scale (GAD-7), and Insomnia Severity Index (ISI) were used to evaluate patients’ emotional states and sleep quality. These scales were assessed before, after, and at a 1-month follow-up.ResultsCompared to before treatment, the treatment group showed a significant decrease in PHQ-9 scores (p < 0.05, Cohen’s d = 1.26), GAD-7 scores (p < 0.05, Cohen’s d = 1.10), and ISI scores (p < 0.05, Cohen’s d = 0.94) after treatment. Similarly, at the 1-month follow-up, significant decreases were observed in PHQ-9 scores (p < 0.05, Cohen’s d = 1.11), GAD-7 scores (p < 0.05, Cohen’s d = 0.88), and ISI scores (p < 0.05, Cohen’s d = 0.94). In contrast, the control group demonstrated no statistically significant differences in PHQ-9, GAD-7, or ISI scores after treatment or at the 1-month follow-up (p > 0.05). Between the two groups, statistically significant improvements (p < 0.05) were observed in PHQ-9 scores (Cohen’s d = 1.47), GAD-7 scores (Cohen’s d = 1.61), and ISI scores (Cohen’s d = 1.06) after treatment. At the 1-month follow-up, statistically significant differences (p < 0.05) between the two groups were also noted in PHQ-9 scores (Cohen’s d = 1.10), GAD-7 scores (Cohen’s d = 0.87), and ISI scores (Cohen’s d = 0.92).ConclusionPressing needle therapy significantly improves the mental health and sleep quality of patients recovering from COVID-19. It enhances their quality of life, promotes early recovery, and is simple and easy to administer, making it a treatment worthy of clinical application.Clinical trial registrationhttps://www.chictr.org.cn/.

SARS-CoV-2 Omicron XBB infections boost cross-variant neutralizing antibodies, potentially explaining the observed delay of the JN.1 wave in some Brazilian regions

ObjectivesThe SARS-CoV-2 JN.1 lineage emerged in late 2023 and quickly replaced the XBB lineages, becoming the predominant Omicron variant worldwide in 2024. We estimate the epidemiological impact of this SARS-CoV-2 lineage replacement in Brazil and we further assessed the cross-reactive neutralizing antibody (NAb) responses in a cohort of convalescent Brazilian patients infected during 2023. MethodsWe analyzed the evolution of SARS-CoV-2 lineages and severe acute respiratory infection (SARI) cases in Brazil between July 2023 and March 2024. We evaluated the cross-reactive NAb responses to the JN.1 variant in a cohort of convalescent Brazilian patients, both before and after infection with XBB.1* lineages. ResultsJN.1 replaced XBB with similar temporal dynamics across all country regions, though its epidemiological impact varied between locations. The Southeastern, Southern, and Central-Western regions experienced a brief XBB wave around October 2023, shortly before the introduction of JN.1, without any immediate upsurge of SARI cases during viral lineage replacement. By contrast, the Northeastern and Northern regions did not experience an XBB wave in the latter half of 2023 and displayed a rapid surge in SARI cases driven by the emergence of the JN.1. We found that recent XBB infections in the Brazilian population significantly boosted cross-reactive NAb levels against JN.1. ConclusionsThe XBB wave observed in the second half of 2023 in some Brazilian states likely acted as a booster for population immunity, providing short-term protection against JN.1 infections and delaying the rise of SARI cases in certain regions of the country.

Unveiling the hidden link: elevated platelets and T cell subsets in 5% of moderate COVID-19 patients 48 days post-onset.

Platelets are hyperactived during acute COVID-19, promoting clotting and modulating immune-cell responses. Immune thrombocytopenia in adults can manifest as an uncommon complication resulting from various viral infections or as a rare adverse event associated with vaccination. However, their role in convalescent COVID-19 patients remains underexplored. This study examines platelet dynamics early in the pandemic, 48 days post-symptom onset, in unvaccinated patients. This longitudinal study included 298 unvaccinated COVID-19 patients (17 mild, 281 moderate) from multiple centers. Clinical evaluations and peripheral lymphocyte subset analyses via flow cytometry were conducted upon admission and on day 48 post-symptom onset (DPSO 48). At DPSO 48, 5.3% of moderate COVID-19 patients exhibited high platelet counts (>300×109/L), associated with elevated total T-cells (26.4%), CD4 T-cells (24.4%), CD8 T-cells (36.9%), and Tregs (33.9%) compared to patients with normal platelet counts. However, the CD4/CD8 T-cell ratio and T-cell subset frequencies remained unaffected, indicating ongoing T-cell homeostasis restoration. Additionally, a significant positive correlation (r=0.636, p=0.03) was found between platelet counts and B cells in patients with elevated platelet counts. Platelets may play a pivotal role in immune regulation during the recovery phase of COVID-19. Targeting platelets and their secreted mediators could improve immune balance in patients with immune disorders, highlighting a potential therapeutic approach for enhancing recovery in post-COVID-19 patients.

Reduced contrast sensitivity function and outer retina thickness in convalescent Vogt-Koyanagi-Harada disease.

To evaluate contrast sensitivity function (CSF) in convalescent Vogt-Koyanagi-Harada (VKH) disease and investigate the relationship between CSF and chorioretinal thickness in VKH patients with and without sunset glow fundus (SGF). This is a cross-sectional study. Seventy-six eyes of VKH patients and 56 eyes of normal controls were evaluated. Patients were divided into SGF and non-SGF groups. The best-corrected visual acuity (BCVA) of all the participants was ≤0.0 logMAR. Their CSF and macular chorioretinal thickness were measured with quantitative CSF (qCSF) and Optical Coherence Tomography (OCT) and compared using repeated measures analysis of variance at the group level. Relationships between CSF and macular chorioretinal thickness were evaluated using generalized estimating equations. The CSF was significantly impaired in the SGF group compared to that in the control group (p = 0.001), especially at medium and high spatial frequencies. No significant CSF difference was found between the non-SGF group and control group, nor between the SGF and non-SGF groups. Compared to the controls, outer retinal thickness (ORT) in both VKH subgroups was significantly reduced (P < 0.001 or 0.005, respectively), although their outer nuclear layer thickness (ONLT) and choroidal thickness (CT) were not significantly different (both P = 1.000, P = 0.829 or 0.112, respectively). We found no significant correlation between CSF metrics and outer retinal thickness. Despite good recovery of visual acuity, reduced CSF and outer retina thickness were found in convalescent VKH patients. CSF may be an important and sensitive metric to evaluate functional vision in VKH disease.

Design, Development and Immunogenicity Study of a Multi-Epitope Vaccine Prototype Against SARS-CoV-2.

Objectives: SARS-CoV-2 caused the COVID-19 pandemic, which overwhelmed global healthcare systems. Over 776 million COVID-19 cases and more than 7 million deaths were reported by WHO in September 2024. COVID-19 vaccination is crucial for preventing infection and controlling the pandemic. Here, we describe the design and development of a next-generation multi-epitope vaccine for SARS-CoV-2, consisting of T cell epitopes. Methods: Immunoinformatic methods were used to derive models for the selection of MHC binders specific for the mouse strain used in this study among a set of human SARS-CoV-2 T cell epitopes identified in convalescent patients with COVID-19. The immunogenicity of the vaccine prototype was tested on humanized-ACE2 transgenic B6.Cg-Tg(K18-ACE2)2Prlmn/J mice by in vitro, in vivo, and ex vivo immunoassays. Results: Eleven binders (two from the Envelope (E) protein; two from the Membrane (M) protein; three from the Spike (S) protein; and four from the Nucleocapsid (N) protein) were synthesized and included in a multi-epitope vaccine prototype. The animals were immunized with a mix of predicted MHC-I, MHC-II, or MHC-I/MHC-II peptide epitopes in Complete Freund's Adjuvant, and boosted with peptides in Incomplete Freund's Adjuvant. Immunization with SARS-CoV-2 epitopes remodeled the lymphocyte profile. A weak humoral response and the significant production of IL-4 and IFN-γ from T cells were found after the vaccination of the animals. Conclusions: The multi-epitope vaccine prototype presented in this study demonstrates immunogenicity in mice and shows potential for human vaccine construction.

Impaired SARS-CoV-2-Specific CD8+ T Cells After Infection or Vaccination but Robust Hybrid T Cell Immunity in Patients with Multiple Myeloma.

Multiple myeloma (MM) patients are at high risk of severe infections including COVID-19 due to an immune dysregulation affecting both innate and adaptive immune responses. However, our understanding of the immune responses to infection and vaccination in MM patients is limited. To gain more detailed insights into infection- and vaccine-elicited T cell immunity in MM, we studied the CD8+ T cell response on the single-epitope level in SARS-CoV-2 convalescent and mRNA-vaccinated MM patients. We compared peptide/MHC class I tetramer-enriched SARS-CoV-2-specific CD8+ T cells and antibody responses in MM patients (convalescent: n = 16, fully vaccinated: n = 5, vaccinated convalescent: n = 5) and healthy controls (HCs) (convalescent: n = 58, fully vaccinated: n = 7) either after infection with SARS-CoV-2 alone, complete mRNA vaccination or SARS-CoV-2 infection and single-shot mRNA vaccination (hybrid immunity). MM patients have lower frequencies and a lower proportion of fully functional virus-specific CD8+ T cells compared to HCs, after both SARS-CoV-2 infection and vaccination. CD8+ T cell memory subset distribution in MM patients is skewed towards reduced frequencies of central memory (TCM) T cells and higher frequencies of effector memory 1 (TEM1) T cells. In contrast, the humoral immune response was comparable in both cohorts after viral clearance. Notably, CD8+ T cell frequencies as well as the humoral immune response were improved by a single dose of mRNA vaccine in convalescent MM patients. MM patients have relative immunological deficiencies in SARS-CoV-2 immunity but benefit from hybrid immunity. These findings underline the relevance of vaccinations in this vulnerable patient group.

Differences in brain activation and connectivity during unaffected hand exercise in subacute and convalescent stroke patients

Patients experiencing severe hemiplegia following a stroke struggle to rehabilitate their affected limbs. Cross-education (CE) training emerges as a promising rehabilitation method due to its safety, simplicity, low risk, and ability to effectively improve muscle strength in the affected limb. However, controversy surrounds the neural mechanisms and clinical applications of CE. To address this, we employed functional near-infrared spectroscopy to monitor the response of regions of interest (ROI) and functional connectivity in patients with stroke experiencing severe hemiplegia during one session of 50% maximal voluntary contraction (MVC) strength training with less-affected hand in both subacute and convalescent phases. Our objective was to compare the two stroke groups to gain insight into the potential utility for unilateral training of the less-affected limb as an effective rehabilitation approach during different phases post of stroke.The findings revealed varying degrees of activation in the ROIs within the affected hemisphere across both groups during the task. Additionally, we found that the subacute stroke patients with severe hemiplegia (SPS) had higher blood oxygen levels in the ipsilesional primary motor (iM1), ipsilesional pre-motor and supplementary motor area (iP-SMA) and contralesional P-SMA (cP-SMA). Functional connectivity strength between the iM1 and contralesional brain regions, as well as between the iP-SMA and ipsilesional ROIs, showed statistically significant differences in SPS compared to convalescent stroke patients with severe hemiplegia (CPS) during a 50% MVC strength training session using the less-affected hand. Significance statementExploring the neural mechanisms underlying one session of 50% MVC strength training with less-affected hand sheds light on a safe therapy. The study enhances our understanding of less-affected hand training and investigates the feasibility as a future rehabilitation approach. Analyzing how one session of 50% MVC strength training with less-affected hand affects brain activation and connectivity could lead to more tailored and effective rehabilitation strategies.

The effect of a new coronavirus infection on hemogram parameters in the early convalescence period of patients with coronary heart disease

Laboratory data, especially a general blood test, play an important role in the treatment of infectious diseases, including COVID-19. However, in patients with coronary heart disease (CHD) and COVID-19, a general blood test is rarely analyzed and is insufficient to fully assess an impact of the new coronavirus infection on patients with cardiac diseases. The aim of the study was to analyze a COVID-19 effect on hemogram parameters in the early recovery period of patients with coronary heart disease. The study was performed at the Kursk City Clinical Hospital for Emergency Medical Care in the years 2021–2022, which involved 58 mature-aged patients (45–59 years old) suffering from coronary heart disease who had a new coronavirus infection and 62 elderly patients suffering from coronary heart disease alone. Morning blood sampling was carried out from the forearm superficial veins into Vacutainer test tubes added with a coagulation activator. In elderly patients, 3–4 weeks after recovery, significant changes in red blood parameters persisted — a decline in the level of peripheral blood erythrocytes, hemoglobin and hematocrit. Elderly patients with coronary heart disease comorbid with a moderate new coronavirus infection, 3–4 weeks later had also higher count of leukocytes, neutrophils, segmented neutrophils and ESR level relative to comparison group. It should be noted that in the early convalescence period elderly patients with coronary heart disease and COVID-19 had significantly elevated ESR, which confirms ongoing sustained inflammatory process. After evaluating the information content according to the calculated Kullback informativeness assessment for analyzed general blood test parameters, it was found to peak for platelet and leukocyte counts as well as ESR level. Thus, among the analyzed indicators in the general blood test, it turned out that platelet and leukocyte count along with ESR level were most informative and of prognostic significance during early convalescent period of elderly patients with coronary heart disease comorbid with a new coronavirus infection, which are proposed to be used as biomarkers of early convalescent period.

Factors Associated With Mortality in Patients With Catheter-related Bloodstream Infection: A Multicenter Retrospective Study.

Catheter-related bloodstream infections (CRBSI) are frequently life-threatening. Several factors have been reported to be related to CRBSI development; however, the factors associated with CRBSI mortality are unclear as they have rarely been studied. This study investigated the factors associated with mortality in patients with CRBSI, specifically focusing on nutritional factors. This retrospective, multicenter study included in-patients with acute conditions and convalescent patients diagnosed with a CRBSI between January 2019 and December 2021 at 33 hospitals (23 general hospitals, two mixed-care hospitals, and eight convalescent hospitals). The primary outcome was death. Unadjusted and multivariable logistic regression analysis was performed to identify factors associated with mortality. A total of 453 patients with CRBSI were enrolled. The causes of death were analyzed for 382 (84.3%) who survived CRBSI and 71 (15.7%) who died. Multivariable analysis revealed that Candida detected in blood culture [adjusted odds ratio (aOR)=2.72, 95% confidence interval (CI)=1.15-6.41; p=0.025)], CRBSI onset within 30 days of catheter insertion (aOR=2.28, 95% CI=1.27-4.09; p=0.005), concurrent infection (aOR=2.07, 95% CI=1.19-3.60; p=0.009), low serum albumin level (aOR=1.64, 95% CI=1.02-2.63; p=0.044), and elevated C-reactive protein level (aOR=1.05, 95% CI=1.01-1.10; p=0.028) were risk factors for mortality, whereas the use of a peripherally inserted central catheter was associated with a reduced risk of CRBSI mortality (aOR=0.30, 95% CI=0.13-0.69; p=0.004). Enhanced monitoring of factors, such as candida detected in blood culture, CRBSI onset within 30 days of catheter insertion, concurrent infection, low serum albumin level, elevated C-reactive protein (CRP) level and the use of a peripherally inserted central catheter (PICC), is crucial for mitigating CRBSI severity and risk of death.

The role of cardiopulmonary rehabilitation in the recovery of right ventricular function and right ventricular-pulmonary artery coupling in convalescent COVID-19 patients

Abstract Introduction Coronavirus disease-19 (COVID-19) is predominantly a respiratory disease, but simultaneous cardiovascular impairment has been documented, even in the post-acute phase. Subclinical right ventricular (RV) dysfunction is often described and mainly attributed to parenchymal lung damage (ARDS) or pulmonary vascular complications such as pulmonary embolism. Cardiopulmonary rehabilitation programs play an integral part in the long-term management of chronic cardiovascular and pulmonary diseases and lately have been proven useful in managing post-COVID-19 sequelae. Purpose The aim of this study is to assess the impact of a post-COVID-19 rehabilitation program in the recovery of right ventricular function and right ventricular-pulmonary artery coupling in convalescent COVID-19 patients. Methods 40 convalescent COVID-19 patients were evaluated one and three months after the acute phase of the disease. 30 subjects participated in a 3-month cardiopulmonary rehabilitation program (study group) and 10 did not (control group). Right ventricular function echocardiographic parameters (right ventricular global longitudinal strain (RVGLS) and pulmonary artery systolic pressure (PASP)) were evaluated and right ventricular-arterial coupling (RVAC) was estimated via the RVGLS/PASP ratio. Results A total of 40 patients were included in this study, of whom 30 underwent cardiopulmonary rehabilitation. There were no major differences in the prevalence of cardiovascular risk factors between the two groups. When examining right ventricular parameters at baseline, RVGLS (Rehabilitation: -23.1 (4.1) % vs. No rehabilitation: -23.0 (4.7) %, p=0.94) and PASP (Rehabilitation: 28 (6) mmHg vs. No rehabilitation: 25 (4) mmHg, p=0.08) did not differ statistically between the two groups. RVAC was also similar at baseline (Rehabilitation: -0.96 (0.28) %/mmHg vs. No rehabilitation: -0.86 (0.27) %/mmHg, p=0.30). At follow-up, patients who underwent cardiopulmonary rehabilitation exhibited a significant improvement in RVGLS (from Τ0: -23.1 (4.2) % to T1: -24.3 (4) %, p&amp;lt;0.001), PASP (from T0: 28 (6) mmHg to T1: 27 (5) mmHg, p=0.016), and RVAC (from T0: -0.86 (0.27) %/mmHg to T1: -0.93 (0.26) %/mmHg, p&amp;lt;0.001). In the no rehabilitation group, RVGLS (from T0: -23.0 (4.7) % to T1: -23.2 (4.4) %, p=0.19), PASP (from T0: 25 (4) mmHg to T1: 25 (4) mmHg, p=0.17), and RVAC (from T0: -0.96 (0.28) %/mmHg to T1: -0.96 (0.27) %/mmHg, p=0.60) were not significantly altered at follow-up. We detected a statistically significant interaction of intervention with RVGLS (p=0.024) and RVAC (p=0.012) (Figure 1). Conclusion Subclinical right ventricular dysfunction is present in convalescent COVID-19 patients. Cardiopulmonary rehabilitation can accelerate the improvement of RVAC by mediating both the RV afterload reduction (PASP) and improving RV function.Figure 1

T cell epitope mapping reveals immunodominance of evolutionarily conserved regions within SARS-CoV-2 proteome.

As SARS-CoV-2 variants continue to emerge capable of evading neutralizing antibodies, it has become increasingly important to fully understand the breadth and functional profile of T cell responses to determine their impact on the immune surveillance of variant strains. Here, sampling healthy individuals, we profiled the kinetics and polyfunctionality of T cell immunity elicited by mRNA vaccination. Modeling of anti-spike T cell responses against ancestral and variant strains of SARS-CoV-2 suggested that epitope immunodominance and cross-reactivity are major predictive determinants of T cell immunity. To identify immunodominant epitopes across the viral proteome, we generated a comprehensive map of CD4+ and CD8+ T cell epitopes within non-spike proteins that induced polyfunctional T cell responses in convalescent patients. We found that immunodominant epitopes mainly resided within regions that were minimally disrupted by mutations in emerging variants. Conservation analysis across historical human coronaviruses combined with in silico alanine scanning mutagenesis of non-spike proteins underscored the functional importance of mutationally-constrained immunodominant regions. Collectively, these findings identify immunodominant T cell epitopes across the mutationally-constrained SARS-CoV-2 proteome, potentially providing immune surveillance against emerging variants, and inform the design of next-generation vaccines targeting antigens throughout SARS-CoV-2 proteome for broader and more durable protection.

Innate immune response in COVID-19: single-cell multi-omics profile of NK lymphocytes in a clinical case series

BackgroundCOVID-19 pandemic caused by the Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) represents the biggest global health emergency in recent decades. The host immune response to SARS-CoV-2 seems to play a key role in disease pathogenesis and clinical manifestations, with Natural Killer (NK) lymphocytes being among the targets of virus-induced regulation.MethodsThis study performed a single-cell multi-omics analysis of transcripts and proteins of NK lymphocytes in COVID-19 patients, for the characterization of the innate immunological response to infection. NK cells were isolated from peripheral blood samples collected from adult subjects divided into 3 study groups: (1) non-infected subjects (Naïve group, n = 3), (2) post COVID-19 convalescent subjects (Healed group, n = 3) and (3) patients that were vaccinated against SARS-CoV-2 (Vaccine group, n = 3). Cells were then analysed by the BD Rhapsody System for the single-cell multi-omics investigation of transcriptome and membrane proteins.ResultsThe bioinformatic analysis identified 5 cell clusters which differentially expressed gene/protein markers, defining NK cell subsets as “Active NK cells” and “Mature NK cells”. Calculating the relative proportion of each cluster within patient groups, more than 40% of the Naïve group cell population was found to belong to Mature NKs, whereas more than 75% of the Vaccine group cell population belonged to the cluster of Active NKs. Regarding the Healed group, it seemed to show intermediate phenotype between Active and Mature NK cells. Differential expression of specific genes, proteins and signaling pathways was detected comparing the profile of the 3 experimental groups, revealing a more activated NK cell phenotype in vaccinated patients versus recovered individuals.ConclusionsThe present study detected differential expression of NK cell markers in relation to SARS-CoV-2 infection and vaccine administration, suggesting the possibility to identify key molecular targets for clinical-diagnostic use of the individual response to viral infection and/or re-infection.

Phenotypic variation in the lipopolysaccharide O-antigen of Salmonella Paratyphi A and implications for vaccine development

Enteric fever remains a major public health problem in South and Southeast Asia. The recent roll-out of the typhoid conjugate vaccine protecting against S. Typhi exhibits great promise for disease reduction in high burden areas. However, some endemic regions remain vulnerable to S. Paratyphi A due to a lack of licensed vaccines and inadequate WASH. Several developmental S. Paratyphi A vaccines exploit O-antigen as the target antigen. It has been hypothesised that O-antigen is under selective and environmental pressure, with mutations in O-antigen biosynthesis genes being reported, but their phenotypic effects are unknown. Here, we aimed to evaluate O-antigen variation in S. Paratyphi A originating from Nepal, and the potential effect of this variation on antibody binding. O-antigen variation was determined by measuring LPS laddering shift following electrophoresis; this analysis was complemented with genomic characterisation of the O-antigen region. We found structural O-antigen variation in <10 % of S. Paratyphi A organisms, but a direct underlying genetic cause could not be identified. High-content imaging was performed to determine antibody binding by commercial O2 monoclonal (mAb) and polyclonal antibodies, as well as polyclonal sera from convalescent patients naturally infected with S. Paratyphi A. Commercial mAbs detected only a fraction of an apparently “clonal” bacterial population, suggesting phase variation and nonuniform O-antigen composition. Notably, and despite visible subpopulation clusters, O-antigen structural changes did not appear to affect the binding ability of polyclonal human antibody considerably, which led to no obvious differences in the functionality of antibodies targeting organisms with different O-antigen conformations. Although these results need to be confirmed in organisms from alternative endemic areas, they are encouraging the use of O-antigen as the target antigen in S. Paratyphi A vaccines.

M protein ectodomain-specific immunity restrains SARS-CoV-2 variants replication.

The frequent occurrence of mutations in the SARS-CoV-2 Spike (S) protein, with up to dozens of mutations, poses a severe threat to the current efficacy of authorized COVID-19 vaccines. Membrane (M) protein, which is the most abundant viral structural protein, exhibits a high level of amino acid sequence conservation. M protein ectodomain could be recognized by specific antibodies; however, the extent to which it is immunogenic and provides protection remains unclear. We designed and synthesized multiple peptides derived from coronavirus M protein ectodomains, and determined the secondary structure of specific peptides using circular dichroism (CD) spectroscopy. Enzyme-linked immunosorbent assay (ELISA) was utilized to detect IgG responses against the synthesized peptides in clinical samples. To evaluate the immunogenicity of peptide vaccines, BALB/c mice were intraperitoneally immunized with peptide-keyhole limpet hemocyanin (KLH) conjugates adjuvanted with incomplete Freund's adjuvant (IFA). The humoral and T-cell immune responses induced by peptide-KLH conjugates were assessed using ELISA and ELISpot assays, respectively. The efficacy of the S2M2-30-KLH vaccine against SARS-CoV-2 variants was evaluated in vivo using the K18-hACE2 transgenic mouse model. The inhibitory effect of mouse immune serum on SARS-CoV-2 virus replication in vitro was evaluated using microneutralization assays. The subcellular localization of the M protein was evaluated using an immunofluorescent staining method, and the Fc-mediated antibody-dependent cellular cytotoxicity (ADCC) activity of the S2M2-30-specific monoclonal antibody (mAb) was measured using an ADCC reporter assay. Seroconversion rates for ectodomain-specific IgG were observed to be high in both SARS-CoV-2 convalescent patients and individuals immunized with inactivated vaccines. To assess the protective efficacy of the M protein ectodomain-based vaccine, we initially identified a highly immunogenic peptide derived from this ectodomain, named S2M2-30. The mouse serum specific to S2M2-30 showed inhibitory effects on the replication of SARS-CoV-2 variants in vitro. Immunizations of K18-hACE2-transgenic mice with the S2M2-30-keyhole limpet hemocyanin (KLH) vaccine significantly reduced the lung viral load caused by B.1.1.7/Alpha (UK) infection. Further mechanism investigations reveal that serum neutralizing activity, specific T-cell response and Fc-mediated antibody-dependent cellular cytotoxicity (ADCC) correlate with the specific immuno-protection conferred by S2M2-30. The findings of this study suggest that the antibody responses against M protein ectodomain in the population most likely exert a beneficial effect on preventing various SARS-CoV-2 infections.

Expressive Writing Intervention Study on the Post-traumatic Growth in Breast Cancer Patients

To explore the mechanism of the effect of expressive writing on the post-traumatic growth of breast cancer patients, and to provide evidence for the rehabilitation of cancer patients. A qualitative interview study was done among 15 young convalescent breast cancer patients who participated in expressive writing intervention in a tertiary A hospital in Guangdong Province, The interview focused on the psychological experience of post-traumatic growth in the process of expressive writing, while content analysis focuses on the content of expressive writing. The interview materials were sorted and analyzed using the Colaizzi 7-step analysis method, and the themes were organized. Results showed that Five themes were extracted from the psychological experience of the post-traumatic growth, including the personality change, the relationship change, the life change, the meaning of illness, the gratitude and dedication. The text content of breast cancer patients' expressive writing includes five dimensions: fact description, emotional expression, self affirmation, cognitive reappraisal, and meaning discovery. There were obvious post-traumatic growth in convalescent young breast cancer patients, while experiencing the negative events and negative psychology of illness. The potential therapeutic mechanism of expressive writing in breast cancer survivors includes five factors: fact description, emotional expression, self affirmation, cognitive reappraisal, and meaning discovery.

Heterogeneity of SARS-CoV-2 immune responses after the nationwide Omicron wave in China.

It remains unclear how previous infections and vaccinations influenced and shaped heterogeneous immune responses against Omicron and its variants in diverse populations in China. After the national wave of Omicron in early 2023, we evaluated serum levels of neutralizing antibodies (nAbs) against Omicron (B.1.1.529) and its variants (BA.5, BF.7, and CH1.1) in 33 COVID-19 convalescents and 40 uninfected vaccinees, using vesicular stomatitis virus-based pseudovirus neutralizing assay. In addition, we followed 34 Delta convalescent patients to compare their immune responses against Omicron before (late 2021) and after the Omicron wave (early 2023). NAbs at the acute phase of the disease were investigated in 50 Omicron inpatients, including 24 vaccinated and 26 unvaccinated patients. Among them, nasal mucosal IgA levels were measured in 42 subjects. Compared to vaccination, breakthrough infections significantly increased the breadth and magnitude of serum nAbs and mucosal IgA levels against Omicron variants. Exposure to Omicron but not Delta elicited stronger pan-Omicron responses. In Omicron inpatients, nAbs continued to rise as vaccination doses increased. However, in both vaccinees and convalescents, a fourth dose vaccination did not elicit higher nAbs against Omicron. Furthermore, nAbs against Omicron variants lasted longer than nAbs against WT SARS-CoV-2. Breakthrough infections of Omicron variants elicited specific immune responses against Omicron compared to vaccination and Delta infection. Although repeated vaccination revealed limited impacts on serum nAbs, populations at high risk of hospitalization may still benefit from continued vaccination.IMPORTANCEThe study described the specific humoral immunity against Omicron and its variants (BA.5, BF.7, and CH1.1) in diverse populations, including Delta-positive convalescent patients, Omicron-infected patients with a previous or current confirmed Delta infection, Omicron-positive patients, and healthy controls. In addition, we followed Delta convalescents for 1 year to evaluate the effect of a booster vaccine, breakthrough infection, and reinfection. Nasal mucosal IgA levels against SARS-CoV-2 were also examined. The findings of this study demonstrated the varied responses of individuals in different states following the outbreak of Omicron, highlighting the potential advantages of ongoing immunization for groups that are more vulnerable and have a greater likelihood of being hospitalized.

Emergence of dysfunctional neutrophils with a defect in arginase-1 release in severe COVID-19.

Neutrophilia occurs in patients infected with SARS-CoV-2 (COVID-19) and is predictive of poor outcomes. Here, we link heterogenous neutrophil populations to disease severity in COVID-19. We identified neutrophils with features of cellular aging and immunosuppressive capacity in mild COVID-19 and features of neutrophil immaturity and activation in severe disease. The low-density neutrophil (LDN) number in circulating blood correlated with COVID-19 severity. Many of the divergent neutrophil phenotypes in COVID-19 were overrepresented in the LDN fraction and were less detectable in normal-density neutrophils. Functionally, neutrophils from patients with severe COVID-19 displayed defects in neutrophil extracellular trap formation and reactive oxygen species production. Soluble factors secreted by neutrophils from these patients inhibited T cell proliferation. Neutrophils from patients with severe COVID-19 had increased expression of arginase-1 protein, a feature that was retained in convalescent patients. Despite this increase in intracellular expression, there was a reduction in arginase-1 release by neutrophils into serum and culture supernatants. Furthermore, neutrophil-mediated T cell suppression was independent of arginase-1. Our results indicate the presence of dysfunctional, activated, and immature neutrophils in severe COVID-19.

Immunologic mediators profile in COVID-19 convalescence

SARS-CoV-2 caused the pandemic situation experienced since the beginning of 2020, and many countries faced the rapid spread and severe form of the disease. Mechanisms of interaction between the virus and the host were observed during acute phase, but few data are available when related to immunity dynamics in convalescents. We conducted a longitudinal study, with 51 healthy donors and 62 COVID-19 convalescent patients, which these had a 2-month follow-up after symptoms recovery. Venous blood sample was obtained from all participants to measure blood count, subpopulations of monocytes, lymphocytes, natural killer cells and dendritic cells. Serum was used to measure cytokines, chemokines, growth factors, anti-N IgG and anti-S IgG/IgM antibodies. Statistic was performed by Kruskal–Wallis test, and linear regression with days post symptoms and antibody titers. All analysis had confidence interval of 95%. Less than 35% of convalescents were anti-S IgM+, while more than 80% were IgG+ in D30. Anti-N IgG decreased along time, with loss of seroreactivity of 13%. Eosinophil count played a distinct role on both antibodies during all study, and the convalescence was orchestrated by higher neutrophil-to-lymphocyte ratio and IL-15, but initial stages were marked by increase in myeloid DCs, B1 lymphocytes, inflammatory and patrolling monocytes, G-CSF and IL-2. Later convalescence seemed to change to cytotoxicity mediated by T lymphocytes, plasmacytoid DCs, VEGF, IL-9 and CXCL10. Anti-S IgG antibodies showed the longest perseverance and may be a better option for diagnosis. The inflammatory pattern is yet present on initial stage of convalescence, but quickly shifts to a reparative dynamic. Meanwhile eosinophils seem to play a role on anti-N levels in convalescence, although may not be the major causative agent. We must highlight the importance of immunological markers on acute clinical outcomes, but their comprehension to potentialize adaptive system must be explored to improve immunizations and further preventive policies.

The Experience of Observational Departments’ Functioning for Treatment of Patients with Tuberculosis from COVID-19 Contact and Convalescents after COVID-19

Relevance. To control COVID-19, a net of special infection hospitals and departments was created, a system of medicaments and protective means’ supply was set up, necessary normative and regulatory documentation was developed and overall vaccination of population was performed in Moscow. Within frames of work for prophylaxis of COVID-19 spread in patients with tuberculosis at in-patient units of the State Budgetary Healthcare Institution of Moscow city «The Moscow Research and Clinical Center for Tuberculosis Control of the Moscow Government Department of Health” (hereinafter referred as the Center), observational departments for treatment of patients with tuberculosis from COVID-19 contact and convalescents after COVID-19. Aims. To evaluate specialized observational departments’ work as part of general anti-epidemic control measure system for COVID- 19 at tuberculosis hospitals. Materials and methods. The observational departments’ work within the period of 2020–2022 with 1075 patients treated including 400 patients from COVID-19 contact areas (37.2%) and 675 convalescent patients after COVID-19 (62.8%), was analyzed. The results obtained during the study were statistically treated by means of application program package Microsoft Office 2007. The quantitative parameters with presumably normal distribution were described with mean arithmetic values (M) and standard deviations (SD), and 95% confidence interval (CI 95%). The estimation of significance of differences between outcomes was evaluated with the Pearson χ2 test. The differences were considered to be statistically significant with p &lt; 0,05. Results and discussion. The evaluation data on functioning efficacy of observational departments for patients with tuberculosis from COVID-19 contact and convalescent patients with tuberculosis after COVID-19 within the large medical institution hospital of physiatry profile. Among all patients, 153 of patients who fell ill with COVID-19 (14.2%; 95% CI [12.21–16.38%]) were determined, which lowered the number of COVID-19 areas at in-patient departments of the Center by 11.8%. The mean timeframes of COVID- 19 determination in general were 8.0 days: 5.4 days among contacts from new coronavirus infection areas and 12.4 days among convalescents at the department for the treatment of patients with tuberculosis and new coronavirus infection. The comparative analysis showed that COVID-19 was more frequently determined in tuberculosis patients from the contact with those who fell ill with COVID-19 (p &lt; 0.001) than in convalescents. Conclusions. During medical care for patients of physiatry profile in Moscow city, a wide range of management decisions consisting in the change of routing system in specialized medical care, was taken. Among them, creation and functioning of observational departments for contact persons from COVID-19 areas and convalescents after COVID-19 play a particular role.Creation of such departments within a large medical institution enabled the contemporary isolation of contact persons from COVID- 19 areas and convalescents after COVID-19 and allowed the additional control of nosocomial infection spread