conclusions these data will be beneficial for designing more advanced antibodies for the recognition of the hbsag in diagnostics. in addition, the results of this study may assist in the design or development of more effective hepatitis b vaccines. results the g145r mutation causes a considerable reduction in the immunogenic activity of the hbsag through a conformational change in the hbsag ant...

hepatitis b vaccination is safe and effective, although breakthrough infection occasionally occurs in those who receive the vaccine and hepatitis b immunoglobulin (hbig) prophylaxis. sequence variation in their antigenic regions is one of the most powerful strategies that are used by viruses to escape recognition by b and t cell-mediated immune responses. the aim of this study was to explore th...

Objective (s):The aim of this study was to determine the correlation between vaccine therapy and appearance of mutations in hepatitis B surface antigen (HBsAg)-positive chronic hepatitis B virus (HBV) patients. Materials and Methods: 16 patients received the HBV vaccine and another 16 individuals from the control group did not. The surface gene was amplified and directly sequenced from samples...

objective (s):the aim of this study was to determine the correlation between vaccine therapy and appearance of mutations in hepatitis b surface antigen (hbsag)-positive chronic hepatitis b virus (hbv) patients. materials and methods: 16 patients received the hbv vaccine and another 16 individuals from the control group did not. the surface gene was amplified and directly sequenced from samples ...

mutations in the human hepatitis b virus (hbv) genome contribute to its escape from host immune surveillance and result in persistent infections. the aim of this study was to characterize the molecular variations of the surface gene and protein in chronically-infected patients from the southern part of iran. the  surface  genes  from  12  hbv  chronic  carriers  were  amplified, sequenced  and ...

abstract mutations have been described in all of the four open reading frames of the hepatitis b virus (hbv), however, from a clinical perspective the surface escape mutant is the most troublesome. hepatitis b surface antigen (hbsag) variants may impair diagnosis, or allow the virus to escape vaccine-induced immunity or passive immunoglobulin therapy. hbv mutants with amino acid substitutions, ...

HBV is a member of Hepadnavirus genus. HBV is a DNA virus with a diameter of 42 nm consisting of an outer lipid envelope which contains proteins HBsAg, pre-S1 and pre-S2. HBsAg is a product of ‘s’ gen. The s geneinvolves ‘a’ epitope124. -147. codones and this region is the affecting region for anti-HBs antibody binding. Vaccine /Immunglobulin escape mutations occur at HBV DNA s gene’s ‘a determ...

BACKGROUND Hepatitis B virus (HBV) infection is a major global health burden with distinct geographic public health significance. Oman is a country with intermediate HBV carrier prevalence; however, little is known about the incidence of HBV variants in circulation. We investigated the HBV genotype distribution, the occurrence of antiviral resistance, and HBV surface antigen (HBsAg) escape muta...

Influenza viruses steadily evolve to escape detection by antibodies, necessitating vaccine updates. A new study uses a massively parallel approach, deep mutational scanning, to catalogue antibody escape mutations. This approach defines potential pathways of viral evolution, beyond those already observed in natural infections, and may help predict its future directions.

Background HIV-1 is capable of evading CTL immune response through mutations in residues both within the epitopes and in sequences flanking the epitopes leading to viral diversity a major obstacle for vaccine design. The present study aims at identifying the HLA-restricted CTL escape mutations primarily in the asymptomatic phase, and examining a correlation between such mutations and disease pr...