scholarly journals Characterization of anti-viral immunity in recovered individuals infected by SARS-CoV-2

2020 ◽  
Author(s):  
Ling Ni ◽  
Fang Ye ◽  
Meng-Li Chen ◽  
Yu Feng ◽  
Yong-Qiang Deng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Effective Vaccine ◽  
Quiescent State ◽  
Viral Immunity ◽  
Post Discharge ◽  
Humoral And Cellular Immunity ◽  
Immune Mediated ◽  
Discharged Patients

AbstractThe WHO has declared SARS-CoV-2 outbreak a public health emergency of international concern. However, to date, there was hardly any study in characterizing the immune responses, especially adaptive immune responses to SARS-CoV-2 infection. In this study, we collected blood from COVID-19 patients who have recently become virus-free and therefore were discharged, and analyzed their SARS-CoV-2-specific antibody and T cell responses. We observed SARS-CoV-2-specific humoral and cellular immunity in the patients. Both were detected in newly discharged patients, suggesting both participate in immune-mediated protection to viral infection. However, follow-up patients (2 weeks post discharge) exhibited high titers of IgG antibodies, but with low levels of virus-specific T cells, suggesting that they may enter a quiescent state. Our work has thus provided a basis for further analysis of protective immunity to SARS-CoV-2, and understanding the pathogenesis of COVID-19, especially in the severe cases. It has also implications in designing an effective vaccine to protect and treat SARS-CoV-2 infection.

scholarly journals SARS-CoV-2-specific immune response in COVID-19 convalescent individuals

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yunbao Pan ◽  
Xianghu Jiang ◽  
Liu Yang ◽  
Liangjun Chen ◽  
Xiaojiao Zeng ◽  
...  
Keyword(s):  
Nk Cell ◽  
Neutralizing Antibody ◽  
Effective Vaccine ◽  
Humoral And Cellular Immunity ◽  
Cell Counts ◽  
Healthy Donors ◽  
Antigen Peptide ◽  
Discharged Patients ◽  
Ifn Γ

AbstractWe collected blood from coronavirus disease 2019 (COVID-19) convalescent individuals and investigated SARS-CoV-2-specific humoral and cellular immunity in these discharged patients. Follow-up analysis in a cohort of 171 patients at 4–11 months after the onset revealed high levels of IgG antibodies. A total of 78.1% (164/210) of the specimens tested positive for neutralizing antibody (NAb). SARS-CoV-2 antigen peptide pools-stimulated-IL-2 and -IFN-γ response can distinguish COVID-19 convalescent individuals from healthy donors. Interestingly, NAb survival was significantly affected by the antigen peptide pools-stimulated-IL-2 response, -IL-8 response, and -IFN-γ response. The antigen peptide pools-activated CD8+ T cell counts were correlated with NAb. The antigen peptide pools-activated natural killer (NK) cell counts in convalescent individuals were correlated with NAb and disease severity. Our data suggested that the development of NAb is associated with the activation of T cells and NK cells. Our work provides a basis for further analysis of the protective immunity to SARS-CoV-2 and for understanding the pathogenesis of COVID-19. It also has implications for the development of an effective vaccine for SARS-CoV-2 infection.

scholarly journals Clinical features and outcomes of discharged coronavirus disease 2019 patients: a prospective cohort study

QJM ◽  
2020 ◽  
Vol 113 (9) ◽  
pp. 657-665 ◽  
Author(s):  
X Wang ◽  
H Xu ◽  
H Jiang ◽  
L Wang ◽  
C Lu ◽  
...  
Keyword(s):  
Cohort Study ◽  
Clinical Outcomes ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Close Contact ◽  
Post Discharge ◽  
Global Pandemic ◽  
Discharged Patients ◽  
Suspected Recurrence

Summary Background Coronavirus disease 2019 (COVID-19) is a global pandemic but the follow-up data of discharged patients was barely described. Aim To investigate clinical outcomes, distribution of quarantine locations and the infection status of the contacts of COVID-19 patients after discharge. Design A prospective cohort study. Methods Demographics, baseline characteristics of 131 COVID-19 patients discharged from 3 February 2020 to 21 February 2020 in Wuhan, China were collected and analyzed by reviewing the medical records retrospectively. Post-hospitalization data related to clinical outcomes, quarantine locations and close contact history were obtained by following up the patients every week up to 4 weeks. Results Fifty-three (40.05%) patients on discharge had cough (29.01%), fatigue (7.63%), expectoration (6.11%), chest tightness (6.11%), dyspnea (3.82%), chest pain (3.05%) and palpitation (1.53%). These symptoms constantly declined in 4 weeks post-discharge. Transient fever recurred in 11 (8.4%) patients. Among the discharged patients, 78 (59.5%) underwent chest CT and 2 (1.53%) showed deterioration. A total of 94 (71.8%) patients received SARS-CoV-2 retest and 8 (6.10%) reported positive. Seven (2.29%) patients were readmitted because of fever or positive SARS-CoV-2 retest. After discharge, 121 (92.37%) and 4 (3.05%) patients were self-quarantined at home or community spots, respectively, after a close contact with 167 persons in total who were free of COVID-19 at the endpoint of study. Conclusion The majority of COVID-19 patients after discharge were in the course of recovery. Readmission was required in rare cases due to suspected recurrence of COVID-19. Although no contacted infection observed, appropriate self-quarantine and regular re-examination are necessary, particularly for those who have recurred symptoms.

scholarly journals Structural and Biophysical Characterization of the HCV E1E2 Heterodimer for Vaccine Development

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1027
Author(s):  
Eric A. Toth ◽  
Andrezza Chagas ◽  
Brian G. Pierce ◽  
Thomas R. Fuerst
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Vaccine Antigen ◽  
Effective Vaccine ◽  
Biophysical Characterization ◽  
Vaccine Candidates ◽  
Glycoprotein Complex ◽  
Vaccine Antigens ◽  
Health Need

An effective vaccine for the hepatitis C virus (HCV) is a major unmet medical and public health need, and it requires an antigen that elicits immune responses to multiple key conserved epitopes. Decades of research have generated a number of vaccine candidates; based on these data and research through clinical development, a vaccine antigen based on the E1E2 glycoprotein complex appears to be the best choice. One bottleneck in the development of an E1E2-based vaccine is that the antigen is challenging to produce in large quantities and at high levels of purity and antigenic/functional integrity. This review describes the production and characterization of E1E2-based vaccine antigens, both membrane-associated and a novel secreted form of E1E2, with a particular emphasis on the major challenges facing the field and how those challenges can be addressed.

scholarly journals Generation and Characterization of DNA Vaccines Targeting the Nucleocapsid Protein of Severe Acute Respiratory Syndrome Coronavirus

2004 ◽  
Vol 78 (9) ◽  
pp. 4638-4645 ◽  
Author(s):  
Tae Woo Kim ◽  
Jin Hyup Lee ◽  
Chien-Fu Hung ◽  
Shiwen Peng ◽  
Richard Roden ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Vaccine Development ◽  
Dna Vaccines ◽  
Global Scale ◽  
Target Antigen ◽  
Humoral And Cellular Immunity ◽  
N Protein ◽  
Histocompatibility Complex

ABSTRACT Severe acute respiratory syndrome (SARS) is a serious threat to public health and the economy on a global scale. The SARS coronavirus (SARS-CoV) has been identified as the etiological agent for SARS. Thus, vaccination against SARS-CoV may represent an effective approach to controlling SARS. DNA vaccines are an attractive approach for SARS vaccine development, as they offer many advantages over conventional vaccines, including stability, simplicity, and safety. Our investigators have previously shown that DNA vaccination with antigen linked to calreticulin (CRT) dramatically enhances major histocompatibility complex class I presentation of linked antigen to CD8+ T cells. In this study, we have employed this CRT-based enhancement strategy to create effective DNA vaccines using SARS-CoV nucleocapsid (N) protein as a target antigen. Vaccination with naked CRT/N DNA generated the most potent N-specific humoral and T-cell-mediated immune responses in vaccinated C57BL/6 mice among all of the DNA constructs tested. Furthermore, mice vaccinated with CRT/N DNA were capable of significantly reducing the titer of challenging vaccinia virus expressing the N protein of the SARS virus. These results show that a DNA vaccine encoding CRT linked to a SARS-CoV antigen is capable of generating strong N-specific humoral and cellular immunity and may potentially be useful for control of infection with SARS-CoV.

scholarly journals Characterization of Patients Who Return to Hospital Following Discharge from Hospitalization For COVID-19

2020 ◽  
Author(s):  
Sulaiman Somani ◽  
Felix Richter ◽  
Valentin Fuster ◽  
Jessica De Freitas ◽  
Nidhi Naik ◽  
...  
Keyword(s):  
New York ◽  
Intensive Care ◽  
Respiratory Distress ◽  
Hospital Treatment ◽  
Index Hospitalization ◽  
Readmission Rates ◽  
Treatment Dose ◽  
Discharged Patients

Background: Data on patients with coronavirus disease 2019 (COVID-19) who return to hospital after discharge are scarce. Characterization of these patients may inform post-hospitalization care. Methods and Findings: Retrospective cohort study of patients with confirmed SARS-CoV-2 discharged alive from five hospitals in New York City with index hospitalization between February 27th-April 12th, 2020, with follow-up of ≥14 days. Significance was defined as P<0.05 after multiplying P by 125 study-wide comparisons. Of 2,864 discharged patients, 103 (3.6%) returned for emergency care after a median of 4.5 days, with 56 requiring inpatient readmission. The most common reason for return was respiratory distress (50%). Compared to patients who did not return, among those who returned there was a higher proportion of COPD (6.8% vs 2.9%) and hypertension (36% vs 22.1%). Patients who returned also had a shorter median length of stay (LOS) during index hospitalization (4.5 [2.9,9.1] vs. 6.7 [3.5, 11.5] days; Padjusted=0.006), and were less likely to have required intensive care on index hospitalization (5.8% vs 19%; Padjusted=0.001). A trend towards association between absence of in-hospital anticoagulation on index admission and return to hospital was also observed (20.9% vs 30.9%, Padjusted=0.064). On readmission, rates of intensive care and death were 5.8% and 3.6%, respectively. Conclusions: Return to hospital after admission for COVID-19 was infrequent within 14 days of discharge. The most common cause for return was respiratory distress. Patients who returned had higher proportion of COPD and hypertension with shorter LOS on index hospitalization, and a trend towards lower rates of in-hospital treatment-dose anticoagulation. Future studies should focus on whether these comorbid conditions, longer LOS and anticoagulation are associated with reduced readmissions.

scholarly journals Inflammation of Conduction Tissue in Patients with Arrhythmic Phenotype of Myocarditis

2020 ◽  
Vol 9 (11) ◽  
pp. 3470
Author(s):  
Andrea Frustaci ◽  
Romina Verardo ◽  
Maria Alfarano ◽  
Cristina Chimenti
Keyword(s):  
Ventricular Tachycardia ◽  
Influenza A ◽  
Sustained Ventricular Tachycardia ◽  
Ventricular Tachyarrhythmias ◽  
Viral Genomes ◽  
Viral Antigens ◽  
Immune Mediated ◽  
Simplex Virus

Background: Myocarditis can manifest with lone ventricular tachyarrhythmias (LVT). Elective inflammation of conduction tissue (CT) is supposed but unproved. Methods: Forty-two of 420 patients with biopsy proven myocarditis presented with LVT. Twelve of them included CT sections in endomyocardial biopsies. Real-time polymerase chain reaction (PCR) for viral genomes, immunohistochemistry for viral antigens and Toll like receptor 4 (TLR4) were performed. Twelve myocarditis patients with infarct-like or cardiomyopathic phenotype and CT included in tissue section were used as controls. Results: Four of the 12 patients presented non-sustained ventricular tachycardia (nsVT), six with sustained ventricular tachycardia (sVT), two with ventricular fibrillation. CT was inflamed in all LVT patients and not in controls (p < 0.001). PCR was positive for influenza-A virus in two, herpes simplex virus type 2 (HSV2) in one and adenovirus in one with positive CT immunostaining for viral antigens. In eight patients, negative PCR and TLR4 overexpression suggested an immune-mediated pathway. Patients with influenza-A myocarditis and CT infection responded to oseltamivir, those with HSV2 (Herpes Virus 2) and adenovirus infection died. The eight patients with immune-mediated myocarditis were treated with steroids and azathioprine. Seven of them had no more VT(ventricular tachyarrhythmias)during six-month follow-up. Conclusions: Arrhythmic phenotype of myocarditis is associated with CT inflammation/infection. Molecular characterization of CT damage may lead to pharmacologic control of arrhythmias in 75% of cases.

Post Discharge Clinically Overt Venous Thromboembolism in Orthopaedic Surgery Patients with Negative Venography -an Overview Analysis

1996 ◽  
Vol 76 (06) ◽  
pp. 0887-0892 ◽  
Author(s):  
Serena Ricotta ◽  
Alfonso lorio ◽  
Pasquale Parise ◽  
Giuseppe G Nenci ◽  
Giancarlo Agnelli
Keyword(s):  
Venous Thromboembolism ◽  
Orthopaedic Surgery ◽  
Diagnostic Methods ◽  
Future Research ◽  
Post Discharge ◽  
Pharmacological Prophylaxis ◽  
Vein Thrombosis ◽  
Overview Analysis ◽  
Major Orthopaedic Surgery

SummaryA high incidence of post-discharge venous thromboembolism in orthopaedic surgery patients has been recently reported drawing further attention to the unresolved issue of the optimal duration of the pharmacological prophylaxis. We performed an overview analysis in order to evaluate the incidence of late occurring clinically overt venous thromboembolism in major orthopaedic surgery patients discharged from the hospital with a negative venography and without further pharmacological prophylaxis. We selected the studies published from January 1974 to December 1995 on the prophylaxis of venous thromboembolism after major orthopaedic surgery fulfilling the following criteria: 1) adoption of pharmacological prophylaxis, 2) performing of a bilateral venography before discharge, 3) interruption of pharmacological prophylaxis at discharge in patients with negative venography, and 4) post-discharge follow-up of the patients for at least four weeks. Out of 31 identified studies, 13 fulfilled the overview criteria. The total number of evaluated patients was 4120. An adequate venography was obtained in 3469 patients (84.1%). In the 2361 patients with negative venography (68.1%), 30 episodes of symptomatic venous thromboembolism after hospital discharge were reported with a resulting cumulative incidence of 1.27% (95% C.I. 0.82-1.72) and a weighted mean incidence of 1.52% (95% C.I. 1.05-1.95). Six cases of pulmonary embolism were reported. Our overview showed a low incidence of clinically overt venous thromboembolism at follow-up in major orthopaedic surgery patients discharged with negative venography. Extending pharmacological prophylaxis in these patients does not appear to be justified. Venous thrombi leading to hospital re-admission are likely to be present but asymptomatic at the time of discharge. Future research should be directed toward improving the accuracy of non invasive diagnostic methods in order to replace venography in the screening of asymptomatic post-operative deep vein thrombosis.

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