Highly sensitive and quantitative HiBiT-tagged Nipah virus-like particles: A platform for rapid antibody neutralization studies.

Biocontainment regulations restrict the research on NiV to BSL-4 laboratories, thus limiting the mechanistic studies related to viral entry and allied pathogenesis. Understanding the precise process of viral-particle production and host cell entry is critical for designing targeted therapies or particle-based vaccines. In this study, we have synthesized HiBiT-tagged-NiV-VLPs to ease in-vitro BSL-2 particle handling. We propose a simple yet effective approach of generating substantial amount of HiBiT-tagged NiV-VLPs in vitro by co-expressing viral structural proteins in HEK293T cells. Though homologous to parent virus, the incapacitated replication potential facilitates a BSL-2 handling of these particles. The inclusion of a highly sensitive HiBiT tag on these VLPs allows for a quick detection of viral binding and entry, as well as in assessing the efficiency of neutralizing antibodies in vitro using the NanoBiT technology. The HiBiT-tag binds in high affinity with LgBiT (Large BiT an 18 kDa fusion protein and complementary subunit of HiBiT peptide), and the resultant complex elicits high intensity luminescence in the presence of substrate. The VLPs produced were morphologically and functionally identical to the native virus, and the HiBiT-tag permitted their quick application in viral binding, entry, and antibody neutralization assays. "Thus, we report a simple setting for generating HiBiT-NiV VLPs which can be utilized in a BSL-2 laboratory, to concurrently quantify features of NiV assembly, binding and entry. This also offers an alternate-safe and effective platform for viral based antibody neutralization assays in vitro".

Inactivated whole-virion vaccine BBV152/Covaxin elicits robust cellular immune memory to SARS-CoV-2 and variants of concern.

BBV152 is a whole-virion inactivated vaccine based on the Asp614Gly variant. BBV152 is the first alum-imidazoquinolin-adjuvanted vaccine authorized for use in large populations. Here we characterized the magnitude, quality and persistence of cellular and humoral memory responses up to 6 months post vaccination. We report that the magnitude of vaccine-induced spike and nucleoprotein antibodies was comparable with that produced after infection. Receptor binding domain-specific antibodies declined against variants in the order of Alpha (B.1.1.7; 3-fold), Delta (B.1.617.2; 7-fold) and Beta (B.1.351; 10-fold). However, pseudovirus neutralizing antibodies declined up to 2-fold against the Delta followed by the Beta variant (1.7-fold). Vaccine-induced memory B cells were also affected by the Delta and Beta variants. The SARS-CoV-2-specific multicytokine-expressing CD4+ T cells were found in ~85% of vaccinated individuals. Only a ~1.3-fold reduction in efficacy was observed in CD4+ T cells against the Beta variant. We found that antigen-specific CD4+ T cells were present in the central memory compartment and persisted for at least up to 6 months post vaccination. Vaccine-induced CD8+ T cells were detected in ~50% of individuals. Importantly, the vaccine was capable of inducing follicular T helper cells that exhibited B-cell help potential. These findings show that inactivated vaccine BBV152 induces robust immune memory to SARS-CoV-2 and variants of concern that persists for at least 6 months after vaccination.

Cytokine Storm in COVID-19-Immunopathological Mechanisms, Clinical Considerations, and Therapeutic Approaches: The REPROGRAM Consortium Position Paper.

Cytokine storm is an acute hyperinflammatory response that may be responsible for critical illness in many conditions including viral infections, cancer, sepsis, and multi-organ failure. The phenomenon has been implicated in critically ill patients infected with SARS-CoV-2, the novel coronavirus implicated in COVID-19. Critically ill COVID-19 patients experiencing cytokine storm are believed to have a worse prognosis and increased fatality rate. In SARS-CoV-2 infected patients, cytokine storm appears important to the pathogenesis of several severe manifestations of COVID-19: acute respiratory distress syndrome, thromboembolic diseases such as acute ischemic strokes caused by large vessel occlusion and myocardial infarction, encephalitis, acute kidney injury, and vasculitis (Kawasaki-like syndrome in children and renal vasculitis in adult). Understanding the pathogenesis of cytokine storm will help unravel not only risk factors for the condition but also therapeutic strategies to modulate the immune response and deliver improved outcomes in COVID-19 patients at high risk for severe disease. In this article, we present an overview of the cytokine storm and its implications in COVID-19 settings and identify potential pathways or biomarkers that could be targeted for therapy. Leveraging expert opinion, emerging evidence, and a case-based approach, this position paper provides critical insights on cytokine storm from both a prognostic and therapeutic standpoint.

Key Strategies for Clinical Management and Improvement of Healthcare Services for Cardiovascular Disease and Diabetes Patients in the Coronavirus (COVID-19) Settings: Recommendations From the REPROGRAM Consortium.

Patients with cardiovascular disease and diabetes are at potentially higher risk of infection and fatality due to COVID-19. Given the social and economic costs associated with disability due to these conditions, it is imperative that specific considerations for clinical management of these patients be observed. Moreover, the reorganization of health services around the pandemic response further exacerbates the growing crisis around limited access, treatment compliance, acute medical needs, and mental health of patients in this specific subgroup. Existing recommendations and guidelines emanating from respective bodies have addressed some of the pressure points; however, there are variations and limitations vis a vis patient with multiple comorbidities such as obesity. This article will pull together a comprehensive assessment of the association of cardiovascular disease, diabetes, obesity and COVID-19, its impact on the health systems and how best health systems can respond to mitigate current challenges and future needs. We anticipate that in the context of this pandemic, the cardiovascular disease and diabetes patients need a targeted strategy to ensure the harm to this group does not translate to huge costs to society and to the economy. Finally, we propose a triage and management protocol for patients with cardiovascular disease and diabetes in the COVID-19 settings to minimize harm to patients, health systems and healthcare workers alike.

N-Methyl-D-Aspartate Encephalitis our Experience with Diagnostic Dilemmas, Clinical Features, and Outcome.

INTRODUCTION: A neuropsychiatric syndrome characterized by a wide spectrum of clinical manifestations. It is seen in patients with antibodies against NR1-NR2 heteromers of the NMDA receptor. As the spectrum is mainly psychiatric most patients are treated as psychiatric disease resulting in huge diagnostic delay. PATIENT AND METHODS: Here we describe 29 patients with NMDA encephalitis seen by the authors in the last five years. Percentage of Transfected cells showing granular cytoplasmic florescence was considered for positivity and severity both in CSF and serum. Their presenting diagnosis, clinical features and the dilemmas, alarming gaps, laboratory data, response to treatment and relapses are discussed. OBSERVATIONS: All patients presented with a spectrum of psychiatric symptoms varying from panic to severe aggression, seizures, chorea, hemiplegia, catatonia, mitgehen, mutism, delirium, mania and memory problems. EEG is invariably abnormal as against imaging. CONCLUSION: NMDA receptor mediated encephalitis should be suspected in all children and females of adolescent age with refractory neuropsychiatric syndrome. Both CSF and serum should be tested and regular follow up for relapses and neoplasms is mandatory.

Factors Determining the Clinical Spectrum, Course and Response to Treatment, and Complications in Seronegative Patients with Central Nervous System Tuberculosis.

INTRODUCTION: Tuberculous meningitis remains a major health issue in the community affecting young adults of both genders predominantly from rural background. In India, the disease continues to kill 2 people every 3 min or nearly 1000 daily, according to the Tuberculosis Control Society India. Tuberculosis (TB) of central nervous system (CNS) is the most devastating form of TB. As this disease is associated with very high prevalence in young adults and will ultimately contribute to great workforce loss, we decided to assess the factors deciding the disease and its course in our patients. PATIENTS AND METHODS: Seronegative patients with probable CNS TB and attending our outpatient department were included and followed up for 2 years. RESULTS: Low body mass index, low proteins, albumin, and low CD3 and CD4, pulmonary TB appears to be a common denominator in a vast majority of these patients. Delay in diagnosis and hyponatremia contributes to morbidity. The location of exudates causes morbidity when they are seen in optochiasmal region. Bacille Calmette-Guerin (BCG) vaccination status in the community appears to be very small. CONCLUSION: CNS TB causes considerable morbidity and mortality in rural young adults resulting in severe manpower loss. Awareness into the possible role of BCG in reducing the complications of TB, role of nutrition and immunity even in seronegative patients and high-degree suspicion in medical professionals can bring down the burden of this deadly disease in the society.