Molecular and serological characterization of hepatitis B vaccine breakthrough infections in serial samples from two plasma donors

Abstract

Background Although vaccines for hepatitis B virus (HBV) are highly effective, HBV infections in vaccinees occur. Index samples of breakthrough infections are typically anti-HBc negative but HBV DNA positive with protective anti-HBs levels while HBsAg detection may be delayed or absent. HBsAg mutations have been associated with some vaccine breakthrough cases. Methods This research characterizes the serological and molecular profiles of vaccine breakthrough infections in serial samples from two commercially available plasma donor panels. Samples were tested with commercially available assays for HBV antigens and antibodies: HBsAg, HBeAg, anti-HBc, anti-HBc IgM, anti-HBe, and anti-HBs. Different immunoassay approaches for earlier detection of breakthrough infection were explored including hepatitis B core-related antigen (HBcrAg), a research assay for preS2 antigen, and a new prototype ARCHITECT HBsAg assay with improved sensitivity. The prototype HBsAg assay is fully automated and involves no sample pre-treatment. Molecular testing included HBV DNA quantitation and sequencing of preS1, preS2, surface, and basal core promoter/core promoter genes. Results Although the research preS2 antigen assay allowed earlier detection of the breakthrough infections than current HBsAg assays and HBcrAg, the new prototype ARCHITECT HBsAg assay provided the earliest serologic detection. The ability of the new prototype HBsAg assay to detect HBsAg in the presence of anti-HBs was investigated using known concentrations of native HBsAg mixed with anti-HBs from a vaccinee. The results demonstrated that the prototype ARCHITECT assay is more sensitive in detecting HBsAg in the presence of anti-HBs than current HBsAg assays. Sequencing revealed multiple substitutions in preS1, preS2, and S regions for one panel including a rare D144N substitution associated with vaccine breakthrough that emerged with increasing frequency as the breakthrough infection developed. Conclusions When compared with other immunoassay approaches, the new prototype ARCHITECT HBsAg assay allows earlier detection of vaccine breakthrough infections and more sensitive detection of HBsAg in the presence of anti-HBs. Molecular characterization of longitudinal samples demonstrated the progressive appearance of a rare HBsAg mutation associated with vaccine breakthrough.

Molecular and Serological Characterization of Hepatitis B Virus (HBV)-Positive Samples with Very Low or Undetectable Levels of HBV Surface Antigen

“…Only one HSLD sample was anti-HBs-positive. Consistent with our previous observation that the HBsAgNx assay improved the detection of HBsAg in the presence of anti-HBs, 18/86 (20.9%) NAT yield and OBI samples incrementally detected by HBsAgNx were anti-HBs-positive [10,11]. However, a combination of anti-HBs >300 mIU/mL with an extremely low viral load could have limited HBsAg detection (Figure 2).…”

“…None of the samples in this study had the classic sG145R mutation associated with vaccine breakthrough which has been reported at a high prevalence in some studies of OBI (Tables 2 and 3). One OBI HBsAgNx-positive-anti-HBs-positive sample had a D144N mutation, a rare mutation associated with vaccine breakthrough (Table 3) [10]. Six OBI samples had substitutions at cysteines involved in disulfide bonds within the 'a' determinant (amino acids 124-147) (Table 3).…”

“…We recently reported on the performance of a new, highly sensitive HBsAg assay (ARCHITECT HBsAg NEXT) with an analytical sensitivity of 0.005 IU/mL, a specificity of 99.95-100% in blood donor and diagnostic populations, and the increased detection of early acute and occult hepatitis B infections [9][10][11][12]. The present study significantly expands on our earlier work to evaluate incremental detection by the new HBsAg assay in a larger sample population representing early acute and OBI from five geographic regions and diverse genotypes.…”

A Global View to HBV Chronic Infection: Evolving Strategies for Diagnosis, Treatment and Prevention in Immunocompetent Individuals

“…Molecular dynamic analysis revealed that the antigenic loops in the G145R mutant are not as exposed as those in the wild-type HBsAg, with a reduced immunogenic potential that may lead to vaccine escape [15]. Until now, a few cases of HBV infection with virus harboring MHR mutations among recipients of not-plasma derived vaccines have been reported, particularly in blood donors receiving HBV DNA testing before donations [16,17]. Thus, the possible impact of HBsAg escape mutants on vaccine efficacy should be acknowledged and taken into account.…”

“…Hossain et colleagues recently found that two natural amino acid mutations, lysine at 120 and aspartic acid at 123, were simultaneously responsible for the production of completely undetectable HBsAg (HBsAg with complete loss of antigenicity), when tested using commercial ELISA kits (Rapid II kit from Beacle Inc., Kyoto, and HBs ELISA Kit from Bioneovan Co., Ltd., Beijing, China) [18]. Hopefully, some new HBsAg assay allows earlier detection of vaccine breakthrough infections and more sensitive detection of HBsAg in the presence of anti-HBs [17]. HBV infection should be considered in patients with acute or chronic liver damage in the absence of an alternative diagnosis and despite HBV vaccination and/or negative HBsAg testing.…”