Respiratory syncytial virus

Adult Respiratory Syncytial Virus Infection and Hypoxic Cardiac Arrest—Coexistent or Causal? A Hypothesis-Generating Case Report

Respiratory syncytial virus (RSV) is a well-known pathogen in paediatric patients. However, it also causes substantial morbidity and mortality in adults, posing a major healthcare problem. We present a patient with chronic pulmonary conditions and an acute RSV infection, thus leading to cardiac arrest (CA). We speculate that RSV as the causative agent for CA should be considered in post-resuscitation care. From a wider public health perspective, immuno-naivety for RSV caused by the coronavirus disease 2019 pandemic may induce a severe rise in cases, morbidity, and mortality in the future.

Exploring the management approaches of cytokines including viral infection and neuroinflammation for neurological disorders

Considerable evidence supports that cytokines are important mediators of pathophysiologic processes within the central nervous system (CNS). Numerous studies have documented the increased production of various cytokines in the human CNS in various neurological and neuropsychiatric disorders. Deciphering cytokine actions in the intact CNS has important implications for our understanding of the pathogenesis and treatment of these disorders. The purpose of this study is to discuss the recent research on treating cytokine storm and amyloids, including stroke, Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's condition, Multi-sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS). Neuroinflammation observed in neurological disorders has a pivotal role in exacerbating Aβ burden and tau hyperphosphorylation, suggesting that stimulating cytokines in response to an undesirable external response could be a checkpoint for treating neurological disorders. Furthermore, the pro-inflammatory cytokines help our immune system through a neuroprotective mechanism in clearing viral infection by recruiting mononuclear cells. This study reveals that cytokine applications may play a vital role in providing novel regulation and methods for the therapeutic approach to neurological disorders and the causes of the deregulation, which is responsible for neuroinflammation and viral infection. However, it needs to be further investigated to clarify better the mechanisms of cytokine release in response to various stimuli, which could be the central point for treating neurological disorders.

Development of an intradermal DNA vaccine delivery strategy to achieve single-dose immunity against respiratory syncytial virus

Respiratory syncytial virus (RSV) is a massive medical burden in infants, children and the elderly worldwide, and an effective, safe RSV vaccine remains an unmet need. Here we assess a novel vaccination strategy based on the intradermal delivery of a SynCon® DNA-based vaccine encoding engineered RSV-F antigen using a surface electroporation device (SEP) to target epidermal cells, in clinically relevant experimental models. We demonstrate the ability of this strategy to elicit robust immune responses. Importantly we demonstrate complete resistance to pulmonary infection at a single low dose of vaccine in the cotton rat RSV/A challenge model. In contrast to the formalin-inactivated RSV (FI-RSV) vaccine, there was no enhanced lung inflammation upon virus challenge after DNA vaccination. In summary the data presented outline the pre-clinical development of a highly efficacious, tolerable and safe non-replicating vaccine delivery strategy.

Nonreplicating vaccines can protect african green monkeys from the memphis 37 strain of respiratory syncytial virus

BACKGROUND

We evaluated the immunological responses of African green monkeys immunized with multiple F and G protein-based vaccines and assessed protection against the Memphis 37 strain of respiratory syncytial virus (RSV).

METHODS

Monkeys were immunized with F and G proteins adjuvanted with immunostimulatory (CpG) oligodeoxyribonucleotides admixed with either Alhydrogel or ISCOMATRIX adjuvant. Delivery of F and G proteins via replication incompetent recombinant vesicular stomatitis viruses (VSVs) and human adenoviruses was also evaluated. Mucosally or parenterally administered recombinant adenoviruses were used in prime-boost regimens with adjuvanted proteins or recombinant DNA.

RESULTS

Animals primed by intranasal delivery of recombinant adenoviruses, and boosted by intramuscular injection of adjuvanted F and G proteins, developed neutralizing antibodies and F/G protein-specific T cells and were protected from RSV infection. Intramuscular injections of Alhydrogel (plus CpG) adjuvanted F and G proteins reduced peak viral loads in the lungs of challenged monkeys. Granulocyte numbers were not significantly elevated, relative to controls, in postchallenge bronchoalveolar lavage samples from vaccinated animals.

CONCLUSIONS

This study has validated the use of RSV (Memphis 37) in an African green monkey model of intranasal infection and identified nonreplicating vaccines capable of eliciting protection in this higher species challenge model.

Neurologic complications associated with respiratory syncytial virus

Encephalopathy has been demonstrated to be associated with respiratory syncytial virus bronchiolitis. In this study, the data on all patients less than 14 years of age hospitalized with respiratory syncytial virus bronchiolitis over the past 4 years was reviewed. Patients who had concomitant diagnoses consistent with neurologic disease underwent detailed chart review. There were 964 patients (age 0.1 to 13.6 years) with a diagnosis of respiratory syncytial virus bronchiolitis. Thirty-six of these patients had concurrent neurologic diagnoses. Twenty-four patients were excluded because of preexistent neurologic disorders, probable simple febrile seizures, or a history of epilepsy. Twelve respiratory syncytial virus-positive patients had definite neurologic complications without another recognized cause. Seven of these patients had seizures (predominantly generalized tonic-clonic and one with status epilepticus), three had generalized encephalopathy (marked hypotonia and decreased responsiveness) of whom two also developed esotropia. Two patients developed isolated esotropia. There was an incidence of neurologic complications of 1.2% (0.7% seizures) in a total of 964 patients with respiratory syncytial virus bronchiolitis. This percentage does not include presumed simple febrile seizures or exacerbations of preexisting seizure disorder (further 1.3%). Neurologic complications occur with respiratory syncytial virus bronchiolitis, and physicians and other caregivers should be aware of this entity as well as the favorable prognosis.