Hepatitis C Virus Epitope Immunodominance and B Cell Repertoire Diversity

Despite the advent of effective, curative treatments for hepatitis C virus (HCV), a preventative vaccine remains essential for the global elimination of HCV. It is now clear that the induction of broadly neutralising antibodies (bNAbs) is essential for the rational design of such a vaccine. This review details the current understanding of epitopes on the HCV envelope, characterising the potency, breadth and immunodominance of antibodies induced against these epitopes, as well as describing the interactions between B-cell receptors and HCV infection, with a particular focus on bNAb heavy and light chain variable gene usage. Additionally, we consider the importance of a public repertoire for antibodies against HCV, compiling current knowledge and suggesting that further research in this area may be critical to the rational design of an effective HCV vaccine.

Analysing and Interpreting the Concept and Possible Implementation of Herd Immunity in the Human Population against COVID 19 Infections

Introduction: Herd immunity refers to developing immunity in individuals by acquiring natural immunity or through vaccination. The Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2) was first reported in a city in China, Wuhan. Currently, no vaccines are available to treat and cure the Covid-19 pandemic. Methods: Information was gathered from electronic databases such as PubMed and Google Scholar. These articles were checked for relevance with recent articles and journals were included while older ones were excluded. Data analysis was then performed using MS Excel and SPSS. Results: Current epidemiological evidence suggests different countries have varying infection rates, therefore varying rates of reproduction number. The current minimum threshold required for herd immunity currently stands between 50-66.67%, although rates vary differently across the globe. Conclusion: A vaccine development is anticipated to be critical in controlling the Covid-19. However, there are several limitations, including changing and managing trends at the virus epitope, differences in the reproduction number across different countries and varying geographical locations, underreporting of infection rates across countries across the globe, and the varying infectious nature of the virus among the demographic population. Regarding the presented information, the vaccine development would significantly accelerate herd immunity and play a key role in managing the disease.

Molecular Mimicry between Zika virus and central nervous system inflammatory demyelinating disorders: the role of NS5 Zika virus epitope and PLP autoantigens

Background: Evidences indicate a strong link between Zika virus (ZikV) and neurological complications. Acute myelitis, optic neuritis, polyneuropathy and encephalomyelitis that mimic inflammatory idiopathic demyelination disorders (IIDD) after ZikV infection have been reported in Brazil. In that context, the present study aims to investigate the possible occurrence of molecular mimicry between ZikV antigens and Multiple Sclerosis (MS) autoantigens, the most frequent IIDD of the central nervous system (CNS). Methods: A retrospective cohort study with 305 patients admitted due to suspected arbovirus infection in Rio de Janeiro was performed, all subjects were submitted to neurological examination and biological sample was collected for serologic and molecular diagnostic. Bioinformatics tools were used to analyze the peptides shared between ZikV antigens and MS autoantigens. Results: Of 305 patients, twenty-six were positive for ZikV and 4 presented IDD pattern found in MS cases. Sequence homology comparisons by bioinformatics approach between NS5 ZikV (most common strains) and PLP MS protein revealed a homology of 5/6 consecutive amino acids (CSSVPV/CSAVPV) with 83% identity, deducing a molecular mimicry. In addition, analysis of the 3D structures of both proteins revealed a similar conformation with alpha helix presentation. Conclusions: Molecular mimicry between NS5 Zika virus antigen and PLP MS autoantigens emerge as a possible mechanism for IDD spectrum in genetically susceptible individuals.