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...

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...

A renal transplant recipient became persistently positive for hepatitis B virus (HBV) despite preexisting anti-hepatitis B surface (HBs) antibodies. The antigenicity and immunogenicity of wild-type (wt) and mutant HBs antigens (Ags) were compared. In contrast to wt HBsAg, genetic vaccination with mutant HBsAgs did not induce anti-HBs. Thus, mutations within HBsAg may enable HBV to escape immuno...

Hepatitis B virus (HBV) is responsible for a serious, potentially fatal disease that affects approximately two billion people worldwide. Although an extended HBV immunization program has run since 1991, representing the most effective preventive measure possible, leading to a dramatic reduction of HBV hepatitis incidence, 4.5 million new HBV infections still occur every year. In 1988 the emerge...

Background: The leading cause of mutations in the hepatitis B virus (HBV) genome is high rate nucleotide misincorporation during reverse transcription. Most were found within “a” determinant S gene’s major hydrophilic region (MHR). They resulted escape mutants due to amino acid changes MHR. However, outside MHR can also trigger mutants. Objectives: This study focused on further molecular studie...

HBs protein is encoded by the pre-S and S genome, and the detection of HBs antigen (HBsAg) in sera is an initial step for the diagnosis of hepatitis B virus (HBV) infection. The “a” determinant region (amino acid residues 124–147) is the main epitope for inducing a protective immune response. Mutations in the “a” determinant region, known as escape mutants, affect antigenicity and hinder attemp...

OBJECTIVE To investigate the prevalence of occult HBV infection (OBI) among children and to characterize virology of occult HBV, we conducted an epidemiological survey. METHODS 186 HB-vaccinated infants born to HBsAg-positive mothers were included in the study. Serological tests for HBV markers were performed using commercial ELISA kits. Real-time quantitative PCR and nested PCR were used to ...

The mutation rate and genetic variability of hepatitis B virus (HBV) are crucial factors for efficient treatment and successful vaccination against HBV. Until today, genetic properties of this virus among the Palestinian population remain unknown. Therefore, we performed genetic analysis of the overlapping S and polymerase genes of HBV, isolated from 40 Palestinian patients' sera. All patients ...

Hepatitis B virus (HBV) DNA was extracted from sera of six carriers with hepatitis B e antigen as well as antibody to hepatitis B surface antigen and sequenced within the pre-S regions and the S gene. HBV DNA clones from five of these carriers had point mutations in the S gene, resulting in conversion from Ile-126 or Thr-126 of the wild-type virus to Ser-126 or Asn-126 in three carriers and con...

Background: The antibody response to hepatitis B surface antigen (HBsAg) controls hepatitis B virus infection. The "a" determinant of HBsAg is the most important target for protective antibody response, diagnosis and immunoprophylaxis. Mutations in this area may induce immune escape mutants and affect the performance of HBsAg assays. Objectives: To construct clinically relevant recombinant muta...