Synthetic representative HCV subtypes, including a 1a and 1b genome, dubbed Bole1a and Bole1b, are provided using an inventive method of Bayesian phylogenetic tree analysis, ancestral sequence reconstruction and covariance analysis. Bole1a branches centrally among 390 full-genome sequences used in its design, a carefully curated 143 sequence full-genome dataset, and separate genomic regions including an independent set of 214 E1E2 sequences from a Baltimore cohort. Bole1a is phylogenetically representative of widely circulating strains. Full genome non-synonymous diversity comparison and 9-mer peptide coverage analysis showed that Bole1a is able to provide more coverage (94% and 78% respectively) than any other sequence in the dataset including H77, a traditional reference sequence. Bole1a also provides unsurpassed epitope coverage when compared to all known T cell epitopes.

A method of preparing extracellularly assembled higher order antigen from a native lower order antigen the method comprising the following steps: (i) contacting lower order antigen with a solution comprising a reducing agent for a time and under 5 conditions sufficient to reduce one or more native cysteines; and (ii) removing or diluting the reducing agent or contacting the reduced lower order antigen with an oxidising agent, to elicit assembly of lower order antigen from (i) into an assembled higher order antigen; wherein at least 10% of the lower order antigen is converted to higher order antigen in step (ii) and whereby the assembled higher order antigen 10 displays at least reduced binding to non-neutralizing antibodies compared to the lower order antigen and retains binding to at least one neutralizing antibody. A method of producing a vaccine composition comprising following the steps of the method and then mixing the assembled higher order antigen with a pharmaceutically or physiologically acceptable diluent, carrier or adjuvant. A composition comprising a 15 higher order extracellularly assembled antigen, wherein the assembled antigen displays at least reduced binding to a non-neutralizing antibody compared to a native control higher order antigen. Use of the assembled higher order antigen to stimulate an immune response or for the detection and/or isolation of an immune cell such as a B-cell specific for the antigen.

Provided herein are engineered polypeptides (e.g., Fc polypeptides, Fc polypeptide fragments, Fc fusion proteins, antibodies, and the like) that comprise a variant of an IgG Fc polypeptide (or a portion or fragment thereof), which variants (and the polypeptides that comprise these variants) have one or more improved characteristics over known Fc polypeptides.

A method for treating HBV infection in a subject, comprising administering to the subject an anti-pre-S1 antibody or a fragment thereof at a dose of about 0.1 mg/kg to about 80 mg/kg. Also relates to an anti-pre-S1 antibody or a fragment thereof for use in treating HBV infection.