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...

Hepatitis B viral mutants can emerge in patients as a result of selection pressure from either immune response or treatment options. Mutations that occur within the immunodominant epitopes of hepatitis B surface antigen (HBsAg) allow mutant virus to propagate in the presence of a neutralizing immune response, while wild-type virus is reduced to undetectable levels. HBsAg mutants present as fals...

objective(s) the aim of this study was to characterize the hepatitis b virus surface protein genotypes and sequence variations among hepatitis b virus surface antigen (hbsag) positive chronic patients in hormozgan province, south of iran. materials and methods a total of 8 patients enrolled in this study. the surface gene was amplified and directly sequenced. genotypes and nucleotide/amino acid...

objectives the present study aimed to evaluate the genotypes and prevalence of mutations in a segment of s and rt gene in hbv isolates in southern khorasan, iran. methods this was a population-based study comprising 5,235 randomized samples for hbv screening. a nested-polymerase chain reaction (pcr) test was followed by direct sequencing, and the sequences blast with present sequences of ncbi d...

We developed an immunogen to stimulate multivalent immunity against hepatitis B surface antigen (HBsAg) and hepatitis B core antigens (HBcAg). Immune responses specific for both HBsAg and HBcAg play an important role in controlling the infection. HBsAg-specific antibodies mediate elimination of virions at an early stage of infection and prevent the spread of virus. The immunogen was constructed...

occult hepatitis b (ohb), or persistent hepatitis b virus (hbv) viremia in surface-antigen-hbsag-negative patients, has been recognized as a medical concern during the last decade. the exact magnitude, pathogenesis and clinical relevance of ohb are unclear. this review organizes the published data on ohb and presents an overview of the current hypotheses on ohb's pathogenesis and clinical relev...

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 ...

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...

Mutations in the core promoter and precore regions of HBV cause down-regulation of HBeAg. These mutations are associated with chronic hepatitis, cirrhosis and Hepato Cellular Carcinoma (HCC). This study was carried out to sequence analysis of HBV core gene in HBsAg- positive blood donors in Iran. A total of 50 HBsAg- positive blood donor samples were examined in this study. Serological markers ...

The small envelope protein of hepatitis B virus (HBsAg-S) can self-assemble into highly organized virus like particles (VLPs) and induce an effective immune response. In this study, a restriction enzyme site was engineered into the cDNA of HBsAg-S at a position corresponding to the exposed site within the hydrophilic a determinant region (amino acid [aa] 127-128) to create a novel HBsAg vaccine...